Sony vs. Olympus: Digital Voice Recorders

Digital voice recorders have become increasingly popular over the last few years, as they offer a relatively cheap and reliable alternative to older cassette voice recorders. Digital voice recorders use memory - much like the memory used in your personal pc - to record sound, rather than tape cassettes. Newer recorders tend to have very large memory capacities, despite their small size.

Though there are several brands of digital voice recorders to choose from, two stand out as the most popular at this time: Sony and Olympus. Here we attempt to compare two recording devices, one from each company. Hopefully this information will be helpful in deciding which recorder is more suitable for your needs.

Olympus DM-20 Digital Voice Recorder

The DM-20 is a popular new model by Olympus. It has received high marks in the past for it's large memory capacity (128MB Built-in flash) that provides about 45 hours of voice recording time. In addition, the device is capable of holding 120 minutes of high quality mp3 music. The recorder can hook up to both a mac or pc, so there isn't much of a compatibility issue in uploading/ downloading songs or voice recordings. Physically, the device is really quite sharp (picture below), and is relatively light - 3 oz. This is good news for anyone who travels; it can be easily placed in a pocket or hand bag. The device also has some nice features that make it even more attractive, such as reminder alarms (work much like your alarm clock), different play and play-back modes, files may be saved in WMA or DSS format, and an external microphone. The main draw back to the device is the lack of an on/ off switch - something that should certainly be there. You are forced to hold down the hold button for some time before the device will shut down. Other than this, however, the device is well worth your attention. It currently sells for $180 - $270 dollars, so shop around.

Olympus DM-20 Digital Voice Recorder

Sony's answer to the DM-20 is the ICD-MS515 memory stick digital voice recorder. This device uses removable Memory Stick Media that is very similar to the smart flash cards used in digital cameras and other devices. The ICD-MS515 comes with a relatively small 8mb memory stick that holds about 170 minutes of recording. This is much smaller than the capacity of the DM-20, but it is possible to simply upgrade to larger memory sticks. Some of the nice features of this device are the built-in microphone, the ability to work with Voice To Print Software (allows the conversion of voice recording to text), usb connectivity, and a voice e-mail system (allowing you to send audible voice mail). The device is also very light, weighing slightly less than 3 oz. It's proportions are very similar to that of the Olympus DM-20. Besides the low memory capacity (which can be upgraded at an additional cost), this a very solid and competitive device. It currently sells for around $200.

Bradley James is a senior editor at <a target="_new" href="http://www.scinet.cc">SciNet.cc</a>, a website containing many helpful consumer electronics review articles. For more information on digital voice recorders, please visit our <a target="_new" href="http://www.scinet.cc/articles/digital-voice-recorders/sony-olympus.html">digital voice recorder</a> webpage.

All In One Printers ? Home Office Workhorses

All in one printers, also known as multifunction printers (MFPs), are printers that also can copy, scan, and in some cases, fax. These machines perform all of these functions, generally using a single set of ink cartridges for both printing and copying. They are not much larger than stand-alone printers, making them a great tool for small home offices.

You can find an excellent all-on-one Epson printer for under $200 ? a steal if you ask me. Have you ever priced a copying machine? Good luck finding one for under $750. These little gems produce high quality printouts and color copies that are indistinguishable from the originals. You'd think that these machines would &quot;drink&quot; ink ? I was pleasantly surprised to find that this is not the case. The copying process uses about the same quantity of ink as the printing process.

Most MFPs offer high resolution, photo-quality printouts without sacrificing speed. This makes them ideal for the amateur photographer, the average home owner, or even the college student who needs to print thesis papers and PowerPoint presentations. You can't imagine how helpful it is having a copier in your home. For a few extra dollars, you can pick up a printer with a built in copier and never have to run to Staples again.

The printer market is so competitive right now that you can probably score a significant rebate on an all in one printer. Recently I've seen rebates for as much as $50 off new Epson all-one-printers. Check around, do some price-shopping, and you too can experience the luxury of a low-cost, home copier/printer.

Bill Smith has written hundreds of articles about printers and ink cartridges, some of which can be found at <a target="_new" href="http://www.buythebestbuy.com">http://www.buythebestbuy.com.</a>

Review of Logitech Computer Speakers

When it comes to computer speaker systems, you have a lot of choice. However, there are simply some brands that stand way out in terms of sound quality and dependability, and one of those brands is certainly Logitech. Logitech computer speakers are some of the best on the market, and provide a great deal of clean, powerful sound for a very reasonable price. Logitech offers a variety of computer speaker systems, for relatively inexpensive 2.1 2-speaker systems to the power 5.1 and 6.1 gaming computer systems with multiple surround-sound speakers. Whatever you are looking for in computer speakers, it is likely that Logitech has it.

Logitech x-230 2.1 2-Piece Dual Drive Computer Speakers

Manufacturers Description: Crank up the audio on your PC with this 2.1-channel computer speaker system and enjoy clean, crisp, consistent sound from your games, music, and more. The Logitech X-230's high-tech subwoofer adjusts itself dynamically to deliver distortion-free bass, while the two wall-mountable satellite speakers use Logitech's patented FDD2 technology to eliminate the uneven sound response created by conventional dual-driver designs. The result: a clear, uniform sound field without the "hot spots" and inconsistency of other dual-driver satellites.

Features:

-32 watts total power (6 watts x 2, plus 20-watt subwoofer)

-Frequency Directed Dual Driver (FDD2) satellite technology produces a uniform sound field for full, rich sound

-Dynamic, real-time bass equalization maximizes bass response while minimizing distortion

-Ported subwoofer design displaces more air for deeper bass

-Headphone jack enables private listening

-Master volume and subwoofer level controls placed for quick, convenient access

-Satellite speaker stands rotate for easy wall-mounting

Price: $50

Value Rating: 9.5 / 10 - This computer speaker system sounds better than some speakers that are $100+ with at least 50 watts of power. It has great crisp sound at nearly all volumes and the bass is surprisingly powerful. Be aware that the subwoofer is not magnetically shielded, and should be kept away from your monitor.

Logitech X-530 5.1 5-Piece Computer Speaker System

Manufacturers Description: Plug the Logitech X-530 into your computer, music player, DVD player, or even PlayStation2 or Xbox game console and immerse yourself in clean, crisp, consistent surround sound from your games, movies, and more. The high-tech subwoofer adjusts itself dynamically to deliver distortion-free bass, while the five wall-mountable satellite speakers use Logitech's patented FDD2 technology to eliminate the uneven sound response created by conventional dual-driver designs. The result: a clear, uniform sound field without the "hot spots" and inconsistency of other dual-driver satellites.

Features:

-70 watts total system power (7.4 watts x 4, plus 15.5-watt center speaker and 25-watt subwoofer)

-Frequency Directed Dual Driver (FDD2) satellite technology produces a uniform sound field for full, rich sound

-Matching front and rear satellites deliver balanced surround sound

-Dedicated center channel makes dialogue clear and intelligible.

-Dynamic, real-time bass equalization maximizes bass response while minimizing distortion

-Ported subwoofer design displaces more air for deeper bass

-Headphone jack enables private listening

-Master volume and subwoofer level controls placed for quick, convenient access

-Satellite speaker stands rotate for easy wall mounting

Price: $60

Value Rating: 9.0 / 10 - A great step up from the X-230. It has the same great sound, with extra bass and a little more all-around power. The extra speakers are great for a surround sound setting. Only downside is that some games are not compatible with the this 5.1 system. Worth the extra $10 for most people.

Logitech X620 6.1 Computer Speakers

Manufacturers Description: More speakers means more sound, more detail, and more intensity. That's what the Logitech X-620 6.1-channel speaker system is all about. Thanks to its 6 satellites, including a dedicated rear center speaker, you can hook it up to your PC or video game console and enjoy your games, music, and movies with sound that truly surrounds you.

Are you looking for powerful bass? Crisp highs and mid-range? The X-620 delivers. Its patented, powerful pressure-driver subwoofer provides twice the bass of conventional designs for smooth, powerful lows, and the satellite speakers provide rich midrange and crisp high-end tones. Even if you don't have a 6.1 sound card, you can still enjoy the benefits of all seven speakers by using the source selector switch.

Got a Sony PlayStation2, Microsoft Xbox, or Nintendo GameCube? Just plug in the X-620 using the convenient video game console adapter and immerse yourself in the explosions, music, and dialogue of your favorite games.

Comes with 6 satellite speakers and a powered 8-inch subwoofer; 70 watts total system power (140 watts peak).

Price: $85

Value Rating: 9.0 / 10 - Another hit from Logitech. This one is much like more expensive home theater systems. Truely one of the best speaker systems in the growing 6.1 class. An important note: prepare to buy a pricey Sound Blaster 6.1 Audigy sound card in order to take full advantage of this speaker system.

Logitech Z-5300e 5.1 2-Piece Surround Sound PC and Gaming Speaker System

Manufacturers Description: Demanding gamers require high power, THX performance, and true surround sound. The Logitech Z-5300e delivers on all counts, with a sleek appearance featuring silver speaker accents and removable black cloth grilles. The system includes a patented dual chamber subwoofer that pounds out twice the bass of conventional designs to deliver deep, loud, and powerful bass. The Z-5300e also features polished aluminum phase-plug satellite drivers that project superb high-end and rich mid-range tones for balanced sound, along with a full-featured SoundTouch wired remote that provides convenient controls for quick adjustments. The satellite speakers' rotating pedestals allow for easy installation on the wall or desktop.

Features:

-280 watts system power (35.25 watts x 4, plus 39-watt center and 100-watt subwoofer)

-PlayStation2, Xbox, and GameCube owners can plug in the Z-5300e using a console adapter

-Silver speaker accents and removable black cloth grilles

-Conveniently control volume and power with the wired remote, which also features a headphone jack

-Enjoy twice the bass of conventional designs with patented subwoofer design

-Satellites fit on a shelf or mounted on the wall

-Use Matrix mode and source selector switch to create breathtaking 5.1 surround sound from stereo, 4-channel, or 5.1 sound sources

Price: $150

Value Rating: 8.0 / 10 - This system is almost too much for your average computer user - but it's great for gamers who demand perfection in their sound system. Even though it will work with game consoles, remember that it is a computer speaker system, and works best with a pc.

Bradley James is a senior editor at <a target="_new" href="http://www.scinet.cc">SciNet.cc</a>, a website containing many helpful consumer electronics review articles. For more information on Logitech computer products, please visit our <a target="_new" href="http://www.scinet.cc/articles/logitechspeakers/logitech-computer-speakers.html">Logitech speakers</a> webpage.

Intel Celeron vs Pentium

The Celeron and Pentium Processors are two of Intel's best selling CPUs. They are found in a majority of home computer systems. When comparing the two processors it should be first understood that there are different types of Pentium processors - the original Pentium all the way to the Pentium 4 (the latest Pentium processor). The Celeron processors are more or less the same, although you will find them in a wide variety of speeds.

The Intel Celeron processor was always designed to be a low-cost alternative to the Pentium processor line. It is much like a car company that offers various priced cars from the luxury sedan to the economy compact. The Celeron is simply a downgraded Pentium, that almost anyone can afford (it is essentially the compact). To begin, Celeron chips have a smaller L2 cache 9128kb compared with 512kb in the Pentium 4 Northwood, which translates into slower processing speeds. In fact, current Celerons have a clock speed limit of about 2.0GHz, where as the Pentium for is capable of speed in excess of 3.0GHz. In addition, the Pentium runs at a lower core voltage because it is more energy effecient (1.75V vs. 1.5V).

In summary, the Pentium 4 is more powerful than the most advanced Celeron processor on the market. However, Intel has planned it to be this way. Many applications will work just great with a Celeron processor, despite a little less power than the Pentium 4. It is a way to save a little cash when buying a new pc - but don't forget the saying "you get what you pay for." Celeron processors are of good Intel quality, but they will never be as good as the Pentium.

This Celeron vs. Pentium review was brought to you by SciNet Science and Technology Search Engine. SciNet is not affiliated with or specifically endorses the Celeron or Pentium processors or the manufacturer, Intel Corp. Please consult the Celeron and Pentium product information and configuration before you purchase either processor. It is also a good idea to seek other up-to-date product reviews and information as necessary.

Bradley James is a senior editor at <a target="_new" href="http://www.scinet.cc">SciNet.cc</a>, a website containing many helpful consumer electronics review articles. For more information on Celeron and Pentium processor technology, please visit our <a target="_new" href="http://www.scinet.cc/articles/celeron-vs-pentium/celeron-pentium.html">Celeron vs Pentium</a> webpage.

How To Stop Junk Faxes From Wasting Your Paper and Toner

Junk faxes waste the resources of every business. It is estimated that they cost businesses tens of millions of dollars a year in wasted paper, toner and fax machine maintenance. There is nothing more aggravating then coming into the office each morning to find a pile of junk faxes promotion everything from mortgage refinancing to septic tank solutions. I don't even have a septic tank!

Junk fax companies have been fined by the federal government and sued repeatedly, but has anyone noticed a reduction in the number of junk faxes? I certainly haven't. The question for most businesses is whether there is a practical way to beat the daily waste of resources caused by junk faxes? Many businesses are using the fax-to-email solution provided through online unified messaging systems.

What is Unified Messaging?

Unified Messaging is a highly flexible communication system that ties all of your communications together. It has the capacity to centralize your voice mail, faxes and email messages in one online area through an email address and single phone number. These systems use their own phone lines and provide you with a separate number, so you don't have to tie up your own or have an additional line installed.

Fax to Email Conversion

One of the best aspects of Unified Messaging systems is the fax-to-email conversion feature. You are provided with a phone number where people can send you faxes and leave voice mail messages. The beauty of the system is that the faxes are then automatically converted to text files and emailed to an inbox.

So, how does this save you money? You simply delete the junk faxes unless, of course, you need to &quot;maximize the potential of your septic tank.&quot; You then read or print out the faxes that are germane to your business. No wasted paper, no wasted toner and no smoke coming out of your fax machine!

An added advantage of the fax-to-email conversion element of unified messaging is the flexibility it gives you. Since the faxes are available to you online, you can print the ones you need at any location. You no longer have the frustrating situation where you are working at home, but need to see a fax that was just sent to your office. You just access your inbox and print it out.

The cost of using unified messaging is very low, particularly when compared to the cost of wasted paper, toner and fax machine maintenance. Depending on the service you use, you may be charged a monthly signup fee, by the minute for phone line usage or both. The best option for your business is entirely dependent upon the number of faxes you expect to receive each month.

Despite the lawsuits and fines issued by government agencies, there is little doubt that junk faxes will continue to bombard your fax machines. Unified messaging provides an inexpensive and practical way to eliminate the cost of junk faxes.

About The Author

Barry Waxler is the President of http://3in1box.com - your unified messaging solution. Visit http://www.3in1box.com to get your FREE unified messaging box or contact Barry at BarryWaxler@3in1box.com

Hard Drive Selection

Perhaps the biggest mistake people make when building their computer(s) is to underestimate the importance of the hard disk drive (HDD). In our modern society, bigger is synonymous with better, so when you go to buy a hard drive you look at how "big" it is, its data capacity. But is that all you should be considering when buying your hard drive?

Like every other component of your computer, the HDD is far too complex a system to describe in any sort of detail here, but hopefully by the end of this article you will know what to look for when you go to buy your new hard drive.

There are 4 primary aspects to look at in a hard drive (in order of importance):

<li>Rotational frequency and average seek time

<li>Buffer size

<li>Internal/external transfer rates

<li>Capacity

Rotational frequency has become a large selling point (5400/7200/10000/15000RPM) recently, so you shouldn't have too much difficulty finding out what the rotational frequency of your HDD is when you go to buy it. Now of course the faster it spins, the faster it can read from the disk (there are other advantages also), but be aware that the faster it spins, the more wear is put on the drive, and the more likely it is to encounter errors and malfunctions later in life. Hard drives are pretty much the only systems within your computer that have moving parts (CD-ROM, floppy disk drives, and fans also have moving parts, but they're all cheap and if they break you won't lose all the data you've accumulated over the course of owning your computer, be sure to back up your data regularly!).

If you know anything about physics or engineering, then you know that moving parts produce friction and wear, and a faster spinning platter (the part that holds the data and spins) means more friction, and therefore more wear on your drive. Of course the faster it spins the faster it can read data from the platter. So what can you do? well again you backup your data as much as possible and you get the fastest spinning drive money can buy (which is 7200RPM for ATA devices (the sort you are buying) and 15000RPM for SCSI and some Serial ATA devices (you might get Serial ATA, that depends on your motherboard)). So look for a "7200RPM" label on the drive you're thinking of getting, it's important!

The "buffer" I'm referring to is the transfer buffer that temporarily stores data to read from or write to the hard drive. The reason for this is that the bus (data channel between the hard drive and the motherboard) can only handle so much information at a time, and it takes a long time for the data to be found and retrieved from a platter (random seek time), so it takes a big chunk of the requested data and stores it in a very fast data buffer to be sent at the bus's convenience. So with a larger buffer you can queue more data for transfer over the bus without having to keep sending requests to slowly find more data from the platters. Some newer drives come with as much as 8MB of buffer capacity, but it is more common to see 2 or 4MB. Usually a drive with a large amount will use that as a selling point and print it on the box/website, otherwise you can assume it has a 2/4MB buffer. My advice is to find one with as much as you can afford.

Now for the transfer rates you're going to need to do some searching, the best way to find these numbers is to go to the manufacturer's website and look at specification sheet for the model you're looking to buy (actually this is the best way to get all the information I've talked about so far). One thing to look out for is that you may read something that says 133MB/s or ATA/133 or SATA150 or 150MB/s, and these are not the numbers you are looking for, those numbers describe the bus connecting the hard drive to the motherboard, and are theoretical peak numbers, which tell us virtually nothing. Also, if you are buying a Maxtor, don't bother looking up actual transfer rates, as Maxtor is apparently afraid to release such information. Not to say Maxtor's are bad drives, actually Maxtor has risen to the top in terms of technical support and they are much more willing to replace broken drives than some other companies, which is important since some ridiculously large amount (something like 10 or 15%) of hard drives are either dead on arrival or die within the first few weeks of use. As with the last two points, when looking at transfer speeds (if you can find them) always try to pick the one with the highest numbers you can afford.

Notice that the first three of the 4 major aspects were all speed related? That was done intentionally to give you a sense of the importance of speed in the hard drive, because they are very very slow creatures, and for your gaming experience you don't need an enormous hard drive so much as a fast one. To increase speed substantially more you can set up a RAID, which is a network of hard drives which (in RAID0 mode) share portions of the same data, such that accessing data takes 1/n time (n = number of hard drives attached) compared to 1 hard drive. To do this you really need a hardware RAID chipset, which are commonly included on higher-end mainboards.

Finally, capacity is an unnecessary nicety. The smallest hard drives you can buy today that are still within those higher speed classes are all about 30GB, which is more than enough for your games. But since games are not everything, and if you happen to be an iTunes member or like to download anime then you will really want some extra space. So I would recommend getting something between 60 and 120GB, any more and you're going to be paying through your teeth, any less and you might be looking to buy a supplementary hard drive in a couple years. And, oh yeah, 300GB hard drives from Maxtor are out, but they are comparatively slow, so I wouldn't recommend getting one for gaming, I like to stick to single platter drives (40-100GB usually), as they produce less heat and are less likely to break down on me.

That is really all you need to know in order to make a good choice when upgrading your hard drive or buying one for a new computer. Of course there are many other resources on the web if you would like more detail on the inner working of hard drives.

About The Author

J A Carpunky <a href="http://www.computer-gaming-system.com" target="_new">http://www.computer-gaming-system.com</a> - visit our website for further information.

Routing, Routed, and Non-Routable Protocols

ROUTING PROTOCOLS

A generic term that refers to a formula, or protocol, used by a router to determine the appropriate path over which data is transmitted. The routing protocol also specifies how routers in a network share information with each other and report changes. The routing protocol enables a network to make dynamic adjustments to its conditions, so routing decisions do not have to be predetermined and static.

Routing, Routed and Non-Routable Protocols

ROUTING | ROUTED | NON-ROUTABLE

ROUTING PROTOCOLS

ROUTING PROTOCOLS are the software that allow routers to dynamically advertise and learn routes, determine which routes are available and which are the most efficient routes to a destination. Routing protocols used by the Internet Protocol suite include:

? Routing Information Protocol (RIP and RIP II).
? Open Shortest Path First (OSPF).
? Intermediate System to Intermediate System (IS-IS).
? Interrior Gateway Routing Protocol (IGRP).
? Cisco's Enhanced Interior Gateway Routing Protocol (EIGRP).
? Border Gateway Protocol (BGP).

Routing is the process of moving data across two or more networks. Within a network, all hosts are directly accessable because they are on the same

ROUTED PROTOCOLS

ROUTED PROTOCOLS are nothing more than data being transported across the networks. Routed protocols include:

? Internet Protocol
o Telnet
o Remote Procedure Call (RPC)
o SNMP
o SMTP
? Novell IPX
? Open Standards Institute networking protocol
? DECnet
? Appletalk
? Banyan Vines
? Xerox Network System (XNS)

Outside a network, specialized devices called ROUTES are used to perform the routing process of forwarding packets between networks. Routers are connected to the edges of two or more networks to provide connectivity between them. These devices are usually dedicated machines with specialized hardware and software to speed up the routing process. These devices send and receive routing information to each other about networks that they can and cannot reach. Routers examine all routes to a destination, determine which routes have the best metric, and insert one or more routes into the IP routing table on the router. By maintaining a current list of known routes, routers can quicky and efficiently send your information on it's way when received.

There are many companies that produce routers: Cisco, Juniper, Bay, Nortel, 3Com, Cabletron, etc. Each company's product is different in how it is configured, but most will interoperate so long as they share common physical and data link layer protocols (Cisco HDLC or PPP over Serial, Ethernet etc.). Before purchasing a router for your business, always check with your Internet provider to see what equipment they use, and choose a router, which will interoperate with your Internet provider's equipment.

NON-ROUTABLE PROTOCOLS

NON-ROUTABLE PROTOCOLS cannot survive being routed. Non-routable protocols presume that all computers they will ever communicate with are on the same network (to get them working in a routed environment, you must bridge the networks). Todays modern networks are not very tolerant of protocols that do not understand the concept of a multi-segment network and most of these protocols are dying or falling out of use.

? NetBEUI
? DLC
? LAT
? DRP
? MOP

RIP (Routing Information Protocol)

RIP is a dynamic internetwork routing protocol primary used in interior routing environments. A dynamic routing protocol, as opposed to a static routing protocol, automatically discovers routes and builds routing tables. Interior environments are typically private networks (autonomous systems). In contrast, exterior routing protocols such as BGP are used to exchange route summaries between autonomous systems. BGP is used among autonomous systems on the Internet.

RIP uses the distance-vector algorithm developed by Bellman and Ford (Bellman-Ford algorithm).

Routing Information Protocol

Background

The Routing Information Protocol, or RIP, as it is more commonly called, is one of the most enduring of all routing protocols. RIP is also one of the more easily confused protocols because a variety of RIP-like routing protocols proliferated, some of which even used the same name! RIP and the myriad RIP-like protocols were based on the same set of algorithms that use distance vectors to mathematically compare routes to identify the best path to any given destination address. These algorithms emerged from academic research that dates back to 1957.

Today's open standard version of RIP, sometimes referred to as IP RIP, is formally defined in two documents: Request For Comments (RFC) 1058 and Internet Standard (STD) 56. As IP-based networks became both more numerous and greater in size, it became apparent to the Internet Engineering Task Force (IETF) that RIP needed to be updated. Consequently, the IETF released RFC 1388 in January 1993, which was then superceded in November 1994 by RFC 1723, which describes RIP 2 (the second version of RIP). These RFCs described an extension of RIP's capabilities but did not attempt to obsolete the previous version of RIP. RIP 2 enabled RIP messages to carry more information, which permitted the use of a simple authentication mechanism to secure table updates. More importantly, RIP 2 supported subnet masks, a critical feature that was not available in RIP.

This chapter summarizes the basic capabilities and features associated with RIP. Topics include the routing update process, RIP routing metrics, routing stability, and routing timers.

Routing Updates

RIP sends routing-update messages at regular intervals and when the network topology changes. When a router receives a routing update that includes changes to an entry, it updates its routing table to reflect the new route. The metric value for the path is increased by 1, and the sender is indicated as the next hop. RIP routers maintain only the best route (the route with the lowest metric value) to a destination. After updating its routing table, the router immediately begins transmitting routing updates to inform other network routers of the change. These updates are sent independently of the regularly scheduled updates that RIP routers send.

RIP Routing Metric

RIP uses a single routing metric (hop count) to measure the distance between the source and a destination network. Each hop in a path from source to destination is assigned a hop count value, which is typically 1. When a router receives a routing update that contains a new or changed destination network entry, the router adds 1 to the metric value indicated in the update and enters the network in the routing table. The IP address of the sender is used as the next hop.

RIP Stability Features

RIP prevents routing loops from continuing indefinitely by implementing a limit on the number of hops allowed in a path from the source to a destination. The maximum number of hops in a path is 15. If a router receives a routing update that contains a new or changed entry, and if increasing the metric value by 1 causes the metric to be infinity (that is, 16), the network destination is considered unreachable. The downside of this stability feature is that it limits the maximum diameter of a RIP network to less than 16 hops.

RIP includes a number of other stability features that are common to many routing protocols. These features are designed to provide stability despite potentially rapid changes in a network's topology. For example, RIP implements the split horizon and holddown mechanisms to prevent incorrect routing information from being propagated.

RIP Timers

RIP uses numerous timers to regulate its performance. These include a routing-update timer, a route-timeout timer, and a route-flush timer. The routing-update timer clocks the interval between periodic routing updates. Generally, it is set to 30 seconds, with a small random amount of time added whenever the timer is reset. This is done to help prevent congestion, which could result from all routers simultaneously attempting to update their neighbors. Each routing table entry has a route-timeout timer associated with it. When the route-timeout timer expires, the route is marked invalid but is retained in the table until the route-flush timer expires.

Packet Formats
The following section focuses on the IP RIP and IP RIP 2 packet formats illustrated in Figures 44-1 and 44-2. Each illustration is followed by descriptions of the fields illustrated. RIP Packet Format

? Command&#8212;Indicates whether the packet is a request or a response. The request asks that a router send all or part of its routing table. The response can be an unsolicited regular routing update or a reply to a request. Responses contain routing table entries. Multiple RIP packets are used to convey information from large routing tables.

? Version number&#8212;Specifies the RIP version used. This field can signal different potentially incompatible versions.

? Zero&#8212;This field is not actually used by RFC 1058 RIP; it was added solely to provide backward compatibility with prestandard varieties of RIP. Its name comes from its defaulted value: zero.

? Address-family identifier (AFI)&#8212;Specifies the address family used. RIP is designed to carry routing information for several different protocols. Each entry has an address-family identifier to indicate the type of address being specified. The AFI for IP is 2.

? Address&#8212;Specifies the IP address for the entry.

? Metric&#8212;Indicates how many internetwork hops (routers) have been traversed in the trip to the destination. This value is between 1 and 15 for a valid route, or 16 for an unreachable route.

Note: Up to 25 occurrences of the AFI, Address, and Metric fields are permitted in a single IP RIP packet. (Up to 25 destinations can be listed in a single RIP packet.)

RIP 2 Packet Format

? Command&#8212;Indicates whether the packet is a request or a response. The request asks that a router send all or a part of its routing table. The response can be an unsolicited regular routing update or a reply to a request. Responses contain routing table entries. Multiple RIP packets are used to convey information from large routing tables.

? Version&#8212;Specifies the RIP version used. In a RIP packet implementing any of the RIP 2 fields or using authentication, this value is set to 2.

? Unused&#8212;Has a value set to zero.

? Address-family identifier (AFI)&#8212;Specifies the address family used. RIPv2's AFI field functions identically to RFC 1058 RIP's AFI field, with one exception: If the AFI for the first entry in the message is 0xFFFF, the remainder of the entry contains authentication information. Currently, the only authentication type is simple password.

? Route tag&#8212;Provides a method for distinguishing between internal routes (learned by RIP) and external routes (learned from other protocols).

? IP address&#8212;Specifies the IP address for the entry.

? Subnet mask&#8212;Contains the subnet mask for the entry. If this field is zero, no subnet mask has been specified for the entry.

?Next hop&#8212;Indicates the IP address of the next hop to which packets for the entry should be forwarded.

? Metric&#8212;Indicates how many internetwork hops (routers) have been traversed in the trip to the destination. This value is between 1 and 15 for a valid route, or 16 for an unreachable route.

Note: Up to 25 occurrences of the AFI, Address, and Metric fields are permitted in a single IP RIP packet. That is, up to 25 routing table entries can be listed in a single RIP packet. If the AFI specifies an authenticated message, only 24 routing table entries can be specified. Given that individual table entries aren't fragmented into multiple packets, RIP does not need a mechanism to resequence datagrams bearing routing table updates from neighboring routers.

Summary

Despite RIP's age and the emergence of more sophisticated routing protocols, it is far from obsolete. RIP is mature, stable, widely supported, and easy to configure. Its simplicity is well suited for use in stub networks and in small autonomous systems that do not have enough redundant paths to warrant the overheads of a more sophisticated protocol.

Review Questions

Q&#8212;Name RIP's various stability features.
A&#8212;RIP has numerous stability features, the most obvious of which is RIP's maximum hop count. By placing a finite limit on the number of hops that a route can take, routing loops are discouraged, if not completely eliminated. Other stability features include its various timing mechanisms that help ensure that the routing table contains only valid routes, as well as split horizon and holddown mechanisms that prevent incorrect routing information from being disseminated throughout the network.

Q&#8212;What is the purpose of the timeout timer?
A&#8212;The timeout timer is used to help purge invalid routes from a RIP node. Routes that aren't refreshed for a given period of time are likely invalid because of some change in the network. Thus, RIP maintains a timeout timer for each known route. When a route's timeout timer expires, the route is marked invalid but is retained in the table until the route-flush timer expires.

Q&#8212;What two capabilities are supported by RIP 2 but not RIP?
A&#8212;RIP 2 enables the use of a simple authentication mechanism to secure table updates. More importantly, RIP 2 supports subnet masks, a critical feature that is not available in RIP.

Q&#8212;What is the maximum network diameter of a RIP network?
A&#8212;A RIP network's maximum diameter is 15 hops. RIP can count to 16, but that value is considered an error condition rather than a valid hop count.

This article is submitted by Kashif Raza <a target="_new" href="http://www.networkingtutorials.net">http://www.networkingtutorials.net</a>

Emergency Response VSAT Internet Communications

As 2005 begins, there are a number of products on the market which enable Emergency Response Units to have internet connectivity at remote disaster locations. The products marketed this year mount on vehicles from Fire Rescue units to most any type of truck or van, on specially designed trailers utilizing portable generators and in transportable boxes which can be shipped by UPS or Fed X overnight to most any location in the U.S. A response team's greatest challenge is to know enough about how this mobile satellite internet technology works and what the differences are in quality of transmission based on the equipment chosen and services provided by the Satellite Internet Provider.

To make the right decision at the onset of the process of buying vsat mobile satellite internet equipment will save your Government Agency thousands of dollars in the long run. How do you evaluate what the best combination of equipment and service will be? Here is the process I recommend to the Government Agencies I speak to around the country:

1. Determine what you will need to do on the internet in an emergency.

Will you need to send digital pictures to other locations? Will you need to establish a VPN connection to Headquarters? Will you want to &quot;live stream&quot; a camera over the internet? Do you need telephone capability over the net (VOIP) in a very remote location that has no cell phone connectivity? Do you need to connect multiple computers at the remote site engaged in the above activities or engaged in heavy emailing? All but emailing requires either low latency (1/2 second or less) or fast upload speeds (sustained speeds above 128kbps)?..some of these activities need both!

If you need ANY of these capabilities, you need to look seriously at the Enterprise Class of equipment available today. This is not Direcway or Starband powered equipment! They are fine companies; however, in spite of all they can do, the important fact is: These companies can't or won't provide enough upload (in-route) speed or low enough latency to work effectively at the tasks listed above ? period!

2. Determine what type of installation will provide your Emergency Response team the most flexibility in an Emergency.

When time is of the essence, you need a mobile setup that can be taken to a disaster site in a hurry and is available at a moments notice to be on it's way. A self contained vehicle mount is the most popular, in part due to the fact that it was all that was available until 2003 and until recently, the least expensive. Many Government Agencies don't have the budget to have such a vehicle &quot;sit around&quot; waiting for a disaster. They need to utilize the vehicle all the time and have a legitimate concern that when the need arises, the vehicle won't be able to get to a location in the time frame needed??what then? Many Government agencies I speak to have recently opted for a trailer mounted system combined with a portable generator or the &quot;transportable&quot; unit which is two or three &quot;boxes&quot; that contain all the gear needed to quickly establish a broadband connection to the internet and can be shipped overnight by Ground Carriers if needed at a distant location. In this scenario, the monthly service is a minimal cost and when the need arises, can be ramped up to whatever speeds are required in a matter of minutes. This can save the Government Agency an enormous amount over the years. It has only been offered by the &quot;big boys&quot; in this business who have figured out how to make money with this type of service by dedicating transponders that handle more accounts than you normally would have as a result of the infrequent use.

The best way to make sure your investment in this equipment is a wise one is to contact an independent provider who can give you a &quot;No Spin&quot; analysis of your situation and recommend the right solution to your organization.

About the Author:

Randy Scott has been involved in the bi-directional satellite internet industry from it's beginning as a Sr. Sales Engineer, consultant and business owner. Randy is the founder of VSAT U.S., a consulting and sales agent, representing the most prestigious satellite internet providers in the U.S. For more information about mobile VSAT products or current VSAT satellite internet offerings, visit <a target="_new" href="www.vsatus.com">www.vsatus.com<a> or email info@vsatus.com .

Upgrading, Adding or Removing a Video Card, Sound Card, or Other AGP/PCI Card

For Video cards - Most PC video cards these days are AGP. But you COULD be working with PCI, or PCI express. If you're not sure which you have (more then 75% of the time it will be AGP) consult your motherboard manual. If your video card is AGP, you should see a slot smaller then the other slots on your board, and it will be a different color. You can likely also tell your video card if it has a GPU (a processor with a fan on top of it) or a video card company printed on it like Nvidia or Geforce.

To take out your video card in order to switch it for a newer one, or if it simply is not working, remove the screw first that holds it to the case. DO NOT ATTEMPT TO REMOVE THE CARD UNTIL YOU HAVE UNSCREWED IT. You will damage, maybe even destroy your card, and you may damage your AGP, PCI or PCI express slot as well. Your board may then have a simple switch that holds the socket down. Flick this switch up. After the scrue is removed, and the switch is flicked up, pull the card away from the board. Pull it on one side first so when it comes out it comes out on a slant, kind of like a car reversing. It should come out quite easily. To put in a new card, make sure the card you're putting in is properly lined up in the slot, then press the card into the slot. If it dosen't seem to be going in, you may be putting it in the wrong way. The pathways on the one side of the card should be the side that goes into the motherboard slot (these pathways looking like small lines going up one side of the card). Once the card sinks in with almost a click (like RAM), flick the switch down and scrue the card into the place you unscrued it. Start up your PC, make sure the card is working, then put your case back on.

Sound card - Sound cards are pretty easy, and the method for these can be used for any other card, such as network cards and the like (assuming they are all PCI. PCI are the black slots on your board). For installing/removing a PCI card, just unscrue it from the board, pull it out, then put the new one in, and scrue it in. Pretty easy. If you are having troubles, make sure the lines running up one side of the card is the side going into the slot. If you still have troubles, try turning the card around (but still make sure the pathways are facing the slot).

I am a young, aspiring computer engineer into Internet Marketing, hardware, software, web design, SEO and just about anything related to computers. Please come check out my growing PC forum at <a target="_new" href="http://www.markspcforum.com">http://www.markspcforum.com</a>

Where Can I Find The Best Case Mods Online and Save Money?

Are you captivated by the stunning Case Mods you've seen online but shell shocked at some of the prices.

What is a case mod, some of you may ask? Have you every wanted to spice up that boring bland box you call your computer?

Well you can and there are lots of people online with fantastic clever ideas on themes, gee whiz lights, sounds, and much much more. Here is a list of top places where you can get information, buy stuff, and chat with others about your ideas.

If you want great case mod information you should go to the Best Case Scenario;

http://www.thebestcasescenario.com/

There you will get great advice on do it yourself case mod projects that will save you money. You will find "well written and photographed case modding worklog that allows us to follow a modder's project in a step-by-step fashion".

If you want to buy great case mod items at low prices you should go to:

http://www.case-mod.com/store

Their statement sums up what the site is about; "A unique shopping experience for the Hardcore PC Enthusiast! Along with providing an excellent selection of high quality items and offering exceptional and personal customer service, Case-Mod.com has found many unique ways to save you money and make your shopping experience an enjoyable one."

If you want case mod forums and galleries go to;

http://www.casemodgod.com

Do it yourself case modding projects. "If you want guides to dozens of creative modding projects, this is your site"

These sites have great advice and products on all kinds of case mod ideas.

Now First-Ever Star Wars PC (more info at http://www.maxsvr.com/case-mod-information/)

Alienware now has a line of Star Wars PCs. In addition to stunning Star Wars graphics on the case, the systems also come with spectacular Star Wars skins and Wallpaper. (more info at http://www.maxsvr.com/case-mod-information/)

According to Alienware;

"As possibly the most popular movie franchise of all time, Star Wars has appeared on countless products and become an indelible part of pop culture. Despite all of that, however, there has never been a PC that Star Wars fans could call their own. Until now. The first-ever Star Wars PC, the Alienware Aurora: Star Wars Edition, has arrived, bringing together one-of-a-kind Star Wars style and award-winning Alienware power to forever transform your computing experience."

The Star Wars graphics on both the "light side" and the "dark side" versions look as impressive as it gets. (more info at http://www.maxsvr.com/case-mod-information/)

Kevin Taylor is a freelance writer/webmaster and lives in Toronto, Canada. <a target="_new" href="http://www.maxsvr.com/case-mod-information">http://www.maxsvr.com/case-mod-information</a>

5 Ways To Backup Your Data...

The data on your hard drive is the most critical item inside your computer, and the only item which can not be replaced. It may be an unwanted hassle and expense to replace a defective memory module, monitor, or processor, but there is no replacing data once lost.

In addition to the possibility of a simple hard drive failure, the threat of internet borne worms and viruses has become an increasing risk to data loss or corruption. Although you may not be able to provide absolute protection to your hard drive, there are various ways that you can ensure that the data on your hard drive is protected. Five methods of backing up your data are summarized below?

1. USB Flash Drives

Although I am not recommending that flash drives be used for the actual data storage, they are a convenient means of transferring data from one computer to another. Important files can be quickly loaded onto a device such as the MINIDISK-512-DGRY-CS USB 2.0 Flash Drive, and transported to another computer for safe keeping. Installation and operation is extremely simple, and other than perhaps having to install a software driver, the use of a USB flash drive is a matter of having an available USB port on your computer. Just about every computer produced over the last several years has USB ports included, with more modern systems supporting the USB 2.0 standard. USB 2.0 allows for data transfer rates of up to 480 MB/s, which is a tremendous improvement over the original USB speed limit of 12 MB/s, and allows a user to fill their drives with data in a relatively short period of time.

Although the storage capacity of flash drives has increased greatly over the last year or so, users are still limited to common sizes of 512MB and 1GB. Mass storage is obviously not an option, but even 512MB may be enough to backup your &quot;My Documents&quot; folder, several albums of MP3s, or other important files to be stored elsewhere.

2. CD and DVD Writers/Re-Writers

The falling prices of CD and DVD writers/re-writers have made them a staple of just about every modern computer. These devices can typically be found installed in a computer case, but external devices supporting USB 2.0 or Firewire are available for greater flexibility and ease of installation.

A combination drive, such as the NU Technology DBW-521, will provide the user a high speed CD reader/writer, as well as a DVD reader, for under $40. The extremely low price of the drive (and the blank media) makes for an inexpensive means of creating data backups, and the re-writable media increases the convenience by allowing the same disc to be erased and reused many times. The main limitation of using a CD writer for data backups is that the discs are generally limited to a capacity of 700MB per disc. Not nearly enough for a full backup, but adequate for archiving key files.

The popularity of DVD writers/re-writers has surged thanks to dropping prices, and they are pushing the stand alone CD burner towards extinction. DVD media affords the user far more storage capacity than a CD, and DVD burners can generally burn CDs as wells as DVDs. The recent availability of double layer DVD burners, such as the Sony DW-D22A-DO-N, represents a large boost in the capacity of writable DVDs, taking the previous limit of 4.7GB per disc and nearly doubling it to 8.5GB.

With proper storage, CD/DVD media can provide long term storage that can not be jeopardized by hardware failure. The data on a CD or DVD can easily be read by just about any computer, making it a good choice for archiving files that aren't excessively large.

3. External Hard Drives

As the name might imply, external hard drives are generally the same type of drive you might find inside your system, but housed in a smaller, external enclosure of its own. The enclosure will feature at least one data interface (such as Firewire, USB, or Ethernet), and the capacity is only limited by the size of hard drives presently available and the user's budget.

The Ximeta NetDisk is an example of an external hard drive that provides a user the option of connecting an additional 80GB, 120GB, or 160GB of storage to their system by using either a USB 2.0 or Ethernet connection. Installation for such a device is rather simple, and may involve the installation of some basic software, as well as making the necessary connections between the computer and the external enclosure.

The capacity of external hard drives makes them ideal for backing up large volumes of data, and many of these devices simplify the process by including software (or hardware) features to automate the backup.

For example, some Seagate External drives feature a &quot;one-button&quot; backup option right on the case.In addition to being a convenient method of backing up large volumes of files locally, most external hard drives are compact enough to be portable. The inclusion of a common data transfer interface, such as USB, allows an external hard drive to be connected to just about any modern computer for data transfer, or for more than one computer to share the external hard drive as a back up.

4. Additional Hard Drives

By simply adding an additional hard drive to you system, you can protect yourself from data loss by copying it from your primary drive to your secondary drive. The installation of a second hard drive isn't difficult, but does require a basic understanding of the inner working of a computer, which may scare off some users. We do offer a &quot;how-to&quot; section on our site for many tasks such as installing a hard drive into a computer system.

To take the installation of a second hard drive to another level of security and reliability, the hard drives may be installed in a RAID array. RAID stands for a Redundant Array of Independent (or Inexpensive) Disks, and can be configured in several manners. A thorough discussion of RAID and all of its variations would be an article all by itself, but what may be of interest to this discussion is what is known as RAID 1. A RAID 1 array requires two hard drives of equal size to be installed on a RAID controller, which will then mirror one drive to the other in real time. Many motherboards now come with RAID controllers onboard, but the addition of a PCI slot controller card, such as the Silicon Image Sil0680, is an inexpensive purchase that will add RAID to any system. With a RAID 1 array in place, if one hard drive should ever fail, the system won't miss a best by continuing to run on the remaining good drive, and alert the user that one drive may need to be replaced.

5. Online Storage

Online services, such as Xdrive, allow users to upload their files to a server for safe keeping. Although it may be convenient to have the data available wherever an internet connection is available, there are a few limitations.

The services generally charge a monthly fee relative to the amount of storage space required. At Xdrive, for example, 5GB of storage costs $9.95 per month, which can quickly add up to more than one would spend on any of the other options discussed.

Security is supposed to be very tight on these services, but no matter how secure it may seem, it is still just a password keeping prying eyes from your potentially sensitive documents.

The speed of your internet connection will also weigh heavily on the convenience of your backup, and no matter what type of connection you have; it can't compete with local data transfer rates.

Final Words

Although not a comprehensive list of options available for backing up your data, the five items listed provide some simple and relatively affordable means to ensure that your data is not lost. Data loss is an extremely frustrating and potentially costly situation, but one that can be avoided.

http://geeks.com/pix/techtips-11-04-04.htm

Jason Kohrs
<a target="_new" href="http://www.geeks.com">Computer Geeks</a> <a target="_new" href="http://www.geeks.com/pix/techtips.htm">tech tips</a> and <a target="_new" href="http://www.geeks.com/pix/techtips.htm">computer advice</a>

Bluetooth Can Be Cracked!

Nothing is completely safe today. Adobe has recently released a patch for a security hole in different graphical software, so why should Bluetooth be safe?

... and Bluetooth isn't safe off course! ;)

Two researchers of the Tel Aviv University School of Electrical Engineering Systems say they have discovered a technique for taking control of Bluetooth-enabled mobile phones. After you've established a connection with an other cell phone, the attacker can easily make calls with your phone. If there is a Bluetooth connection with a PC, the hacker can even transfer data between his Bluetooth device / cell phone and the hacked computer. Bluetooth can be very dangerous as you can see! Even when the handsets have security features switched on, your cell phone isn't save at all!

Avishai Wool, senior lecturer and Yaniv Shaked, graduate student and both researchers of the Tel Aviv University School of Electrical Engineering Systems have published recently a paper about three methods for forcing a repeat of the pairing process, "Cracking the Bluetooth PIN" ( http://www.eng.tau.ac.il/~yash/shaked-wool-mobisys05/ ). In this paper, a passive attack is described, in which an attacker can find the PIN used during the pairing process. The eye-opening conclusion of these two researchers: "Our results show that using algebraic optimizations, the most common Bluetooth PIN can be cracked within less than 0.06-0.3 seconds. If two Bluetooth devices perform pairing in a hostile area, they are vulnerable to this attack."

A Belgian Master student is making a fresh attempt to keep a list with Bluetooth security links on http://student.vub.ac.be/~sijansse/2e%20lic/BT/welcome.html.

Ollie Whitehousen security researcher of @stake, a digital security consulting firm ( http://www.atstake.com ) has written in October 2003 a paper that "examines methods of assessing the security of Bluetooth devices in relation to the protocol's design and implementation flaws" ( http://www.atstake.com/research/reports/acrobat/atstake_war_nibbling.pdf ).

In general, the most critical point is the 'pairing' - connection procedure of two Bluetooth devices. When a Bluetooth device asks you to re-enter the PIN number for re-pairing, once the two devices are re-connected, the hacker can now easily crack the PIN code.

Links:

- http://www.atstake.com/research/reports/acrobat/atstake_war_nibbling.pdf

- http://student.vub.ac.be/~sijansse/2e%20lic/BT/

- http://www.eng.tau.ac.il/~yash/shaked-wool-mobisys05/

For feedback on this article, please visit <a target="_new" href="http://wallies.info/blog/item/145/index.html">http://wallies.info/blog/item/145/index.html</a>

Walter V. is a self-employed internet entrepreneur and founder-webmaster of several websites, including<br /> wallies.info :: A snappy blog about snappy blue things :: blog | wiki | forum | links - <a target="_new" href="http://wallies.info">http://wallies.info</a><br /> mblo.gs :: A snappy moblog community - <a target="_new" href="http://mblo.gs">http://mblo.gs</a>

RAID Disk Recovery

RAID is short for Redundant Array of Independent (or Inexpensive) Disks, a category of disk drives that employ two or more drives in combination for fault tolerance and performance. RAID disk drives are used frequently on servers and increasingly being employed on personal computers. Array is the operative word, which also dictates what the cure is going to be, when a RAID disk recovery situation arises.

RAID disk repair, as you may expect is quite a complicated process. But the good thing going for it is the chances for retrieving lost data is higher than with most other types of disks because the typical RAID architecture strategically distributes data randomly across the array. What this sort of architecture demands of recovery professionals is to specialize in the disk???s many different levels.

In a nutshell, these are all the levels that the RAID disk recovery team is up against. RAID 0, 1, 0+1; RAID 3, 4; RAID 5; RAID 10; Hardware RAID including: AMI, Compaq, Dell, Adaptec, IBM, etc.; and, Software RAID including Mac OS; Windows Servers including 2K, XP, NT; Linux, Solaris, Novell, etc.

Just some RAID systems that most RAID disk recovery specialists should all be familiar with are: Quantum Snap Server; Maxtor MaxAttach; Adaptec AAA131; Compaq; Dell Perc Systems; IBM; AMI; Mylex; and yes, many others!

The two most common implementations of the RAID architecture are Levels 4 and 5. Level 4 provides block stripping with a parity check. When a data disk fails, the parity data is used to create a replacement disk. Level 5 provides data stripping at the byte level and also stripe error correction information, which results in excellent performance and good fault tolerance. These two types are certainly the best friends of the RAID disk recovery expert as these are the easiest to restore when the situation arises.

Brad Triggs provides more information on Data Recovery at his website:
<a target="_new" href="http://www.data-recovery-central.com">Data-Recovery-Central.com - RAID Data Recovery</a>

10 Things to Ponder Before Moving Your Office Network

Moving the office network? How hard could it be? Anybody who's ever moved the office network knows the risks and challenges associated with this colossal task. This mighty endeavour is not merely a case of logging-off, shutting down and pulling the plug.

The move requires careful, systematic planning, forethought and a little luck. The following considerations provide valuable guide ropes for hauling serious office technology.

Think of the move as the evolutionary-growth to a better network

An office move can provide the perfect opportunity to re-evaluate your IT systems, introduce new technology and upgrade your equipment.

Consider the future of your company and the flexibility your network will need as your company expands. Assess your needs and work out exactly what you will need to add to provide for your future growth.

Hire a network specialist to fine tune your systems

Obtaining expert advice helps cut corners, taking the guesswork out of what equipment you'll need, design and implementation of the network and the difficulties associated with troubleshooting.

&quot;We take great pride in our work. As a reliable, efficient and highly specialised IT company in London, you'll be afforded the peace of mind that with us, your computers and network are in the hands of professionals&quot; says Andrew Cruise, Managing Director of Hypercubic.

You also get an idea of what the costs will be, including the benefits of on-going maintenance and support. Planning the installation process with a professional takes the load off your shoulders and many thorns out of your side.

Save on downtime

Install the new system over the weekend, this way there will be minimal disruption to the business. Think about how many emails, phone calls and enquiries you will be missing if you move during the week. If the installation takes longer, inform clients or users in advance so they know what to expect.

One businessman reported, &quot;Before we moved offices, we sent an email to all of our clients informing them about the move and provided all our clients with contact details. Our manager received valuable business related calls via his mobile phone thanks to this pre-planning&quot;.

Moving valuable, sensitive equipment requires care

Moving several floor-standing servers or a couple of 42u racks may take more than a fat guy with a slipped disk. Depending on the size of the server lifting the equipment may require hoists, trolleys and ropes.

A removal truck is obviously an essential part of the office move, though extra care needs to be taken concerning packaging.

Prepare for impact

Your delicate robotics need to travel comfortably between cushioned barriers, preventing devices from jarring together. Wrapping the equipment in anti-static bubble wrap shields the equipment against magnetic fields, preventing the loss of valuable data.

Equipment should ideally be placed in computer crates. Each crate should be dedicated to one complete system that is labelled for easy identification.

Think seriously about Insurance

When it involves your bread and butter being stored in digital format, ensure you have a back-up plan in case something happens during the move. Most insurance companies offer various policies for insuring computers against theft and damage.

Find out if your new building has the facilities for your network

Be sure to conduct a site survey and evaluate what your network needs are. This helps to curb overspending on equipment and identifies the best possible locations for installing access points. It also ensures that cable runs meet the local building codes.

Things just work better when cabling is installed before the move

Before the move goes ahead, the new network's cabling and network infrastructure should be in place, conveniently ready for each labelled workstation crate to be placed next to the correct plugs, power leads and phone lines.

Power On: Booting-up the network

Expect a few glitches; problems are inevitable with a new network. Hiring a professional at this point is an invaluable asset. Installation support ensures that the company can deal with any unforeseen teething problems during the initial start-up period.

Lastly, don't even think about doing it yourself

Most companies, before seeking advice from professionals, go down the DIY networking route. Unless you have a qualified team, installing a network can turn ugly and about as frustrating as unravelling 3000 feet of fishing line with one hand.

Hypercubic is a London based <a target="_new" href="http://www.hypercubic.co.uk/">IT Support Company</a> specialising in the installation and support of computer networks. Their IT support technologies help save time and effort, especially when moving a network to a new location.

An Introduction to HD-DVD

High density digital versatile disc is a digital optical media format which is being developed. HD DVD is similar to the competing Blu-ray Disc. It is currently in a format war with the Blu ray disc proposed by the Blu ray disc association.

HD DVD has a single layer capacity of 15GB and a double layer capacity of 30GB. The surface layer is 0.6mm thick which is the same thickness of surface layer as standard DVDs.

HD DVD media is less expensive to manufacture than Blu ray discs which require re-tooling of DVD production lines. Another advantage over Blu ray is the common disc structure with DVDs which therefore allows for full backwards compatibility of HD DVD drives which will be able to play both DVDs and CDs. However it is now likely that Blu ray drives will be backwards compatible with DVDs.

HD DVD provides the large capacity storage needed for all sorts of recorded content, including high definition movies and music as well as computer data and files.

There are two kinds of of HD DVD discs for content, the 15GB single layer disc and the dual-layer disc with double capacity, a full 30GB. Using the latest compression technologies, the 30Bg disc can store up to 7 hours of images. Today' DVD has a capacity of 4.7GB and store only 2 hours of standard definition content.

HD DVD discs have a data transfer rate of 36.55Mbps which allows the 24Mbps data stream of digital television broadcasts to be seamlessly recorded.

Using HD DVD in the every day world will have numerous advantage over other optical media technologies. The resilient HD DVD disc has a protective layer which removes the need for a protective cartridge, allowing the development of slim computer drives. The added bulk of a disc cartridge would have also caused any laptops using a cartridge based optical media disc to increase substantially in size to allow for the extra room the drive would need.

Chuck Red runs website on both Blu ray <a target="_new" href="http://www.blueray-media.co.uk">http://www.blueray-media.co.uk</a> and HD DVD formats <a target="_new" href="http://www.hddvd-media.co.uk/">http://www.hddvd-media.co.uk/</a>

ABCs Of DVD Drive Abbreviations

The number of different formats available in DVD drives can be confusing to anyone in the market for one. The list is much longer, but to address a few of the common formats, we have DVD-ROM, DVD-R, DVD-RW, DVD+R, DVD+RW, DVD-RAM ,DVD+R DL and DVD?RW. Wow! This list of common formats is long enough, no wonder it's confusing!

What's with all the Formats?!

The reason for various recordable DVD formats is that no one group owns the technology and different groups have chosen to support one technology over another. There is no industrial standard for manufacturers to reference, so for the time being consumers will have a few choices.

The first thing to address is DVD itself, which stands for Digital Versatile Disc. Some may argue that the V stands for Video, but with the capability to store video, audio, and data files, Versatile is definitely the keyword.

Start with the Basics

A DVD-ROM drive is the only one we will address that does not record. ROM stands for Read Only Memory, and refers to the typical drive that can merely read DVDs, as well as CDs (all DVD drives can read CDs). The Lite-On LTD-163-DO-R has attributes representative of your typical DVD-ROM drive, and features a maximum DVD read speed of 16x and a maximum CD read speed of 48x.

Before getting into the different recordable formats, let's address the basics of what the R and RW stand for, regardless of whether there is a + or ? in the middle. R stands for Recordable, which indicates that the disk may be recorded to only once. RW stands for ReWritable, which indicates that the disc may be recorded to more than once, and are generally rated for 1000 rewrites under good conditions.

The DVD-R/-RW format was developed by Pioneer, and was the first format compatible with stand alone DVD players. The group that promotes the technology calls itself the DVD Forum, which is &quot;an international association of hardware manufacturers, software firms, content providers, and other users&quot; with notable members such as Hitachi, Samsung, and Toshiba. The DVD-R/-RW format is based on CD-RW technology and uses a similar approach to burning discs.

The DVD+R/+RW format is a newer format, also based on CD-RW technology, and compatible with a large percentage of stand alone DVD players. The +R/+RW technology is not supported by the DVD Forum, and its main backing comes from a group called the DVD+RW Alliance. The Alliance &quot;is a voluntary group of industry-leading personal computing manufacturers, optical storage and electronics manufacturers&quot; with members such as Dell, Hewlett Packard, Sony, and Phillips Electronics.

The DVD-RAM format is based on PD-RW (Phase-Differential) drives, and actually uses a cartridge to hold the media (just like its PD-RW predecessor). Some DVD-RAM cartridges are double sided, making them ideal for companies to use as system backup, hence DVD-RAM is usually found only in commercial applications, and most end-users won't ever need to use or see this type of drive. The DVD-RAM standard is also supported by the DVD Forum just like the DVD-R/RW format. However, because of its use of a cartridge (limiting it's compatibility), and the scarcity and price of the media used, DVD-RAM is a distant third when compared to the DVD+R/+RW and DVD-R/?RW technology.

The +R/+RW and ?R/-RW formats are similar, and the main difference DVD+R technology has is the ability to record to multiple layers (with its new DVD+R DL format), where DVD-R can only record to one layer (not all +R drives are capable of dual layer burning, but no -R drives are). The Plextor PX-504U is an example of an external DVD+R/+RW drive capable of recording single layer discs in the +R/+RW format, but also able to read discs recorded by a DVD-R drive.

What is DVD?RW?

DVD?RW is not actually a separate format, but the designation given to drives capable of both ?R/?RW and +R/+RW operation. This type of drive is typically called a &quot;Dual Drive&quot; (not to be confused with a &quot;Double Layer&quot; drive) since it can write to both the +R/+RW and ?R/?RW formats. The Samsung TS-H552 is a DVD?RW drive capable of reading and writing every format discussed so far, and then some. It takes advantage of DVD+R DL (Double Layer) technology available with the +R format, allowing the appropriate media to store virtually double the 4.37 GB capacity of a typical single layer disc.

The other main thing to consider with DVD burners is selecting the correct media. Media for DVD-R, DVD-RW, DVD+R and DVD+RW media may all look the same, but they are slightly different in order to match the specific recording formats. The price of media for either format is generally the same, with RW media costing a good deal more than R media of either format. Double Layer media is even more expensive, and is the only way for an owner of DVD+R DL drive to take advantage of the tremendous capacity increase. As the amount of Double Layer drives increase in the market, the price of the DVD+R DL media is expected to fall with increased production of the media. DVD Burners (as these drive are often referred to) can be picky about the media supported, so be sure to choose your media wisely.

DVD in a Nutshell

DVD-ROM : Reads DVD discs

DVD+R : Writes to DVD+R media (will also typically write to CD-R and CD-RW media)

DVD+RW : Writes to DVD+RW media (will also typically write to DVD+R, CD-R and CD-RW media)

DVD+R DL : Writes to DVD+R DL (Double Layer) media (will also typically write to DVD+R, DVD+RW, CD-R and CD-RW media; many Double Layer drives are ALSO dual drives ? that is, able to write to BOTH +R/RW and ?R/RW media)

DVD-RAM : Writes to DVD-RAM cartridges (not in wide use on consumer market ? mainly a business format; can also read PD-RW discs. Will not usually be able to write to any other format including CD-R or CD-RW)

DVD-R : Writes to DVD-R media (will also typically write to CD-R and CD-RW media)

DVD-RW : Writes to DVD-RW media (will also typically write to DVD-R, CD-R and CD-RW media)

DVD?RW : Writes to DVD-RW and DVD+RW media (will also typically write to DVD-R, DVD+R, CD-R and CD-RW media; typically called &quot;Dual Drives&quot; since it can burn to two different DVD formats)

Final Words

This article took a look at the more common formats of DVD drives in order to shed some light on all the choices available. The differences between them all may be subtle, but the compatibility issues can be quite frustrating. The simple answer to anyone considering a drive is to forget about + and ? by themselves, and shoot for universal compatibility with a good DVD?RW with DVD+R DL support.

<a target="_new" href="http://www.geeks.com/pix/techtips.htm">http://www.geeks.com/pix/techtips.htm</a>

Generation Laptop

In May 2005 U.S hardware history was made.

This was the first time that laptops sold more than desktop computers in a single month. Indeed, Current Analysis, an innovative research firm headquartered in Sterling, Virginia, confirmed that laptop sales leapt to 53.3 per cent of the total PC retail market in May 2005.

Were these figures just a blip on the the computer sales radar? Let your own eyes answer that question for you - Folks using laptops are everywhere! - People checking their emails in coffee shops, students studying interactively in the classroom, business men and women compiling data reports on planes and trains.

So, what current factors contribute to the massive popularity of laptops with the computer buying public?

AFFORDABILITY

Five years ago, you could walk into a computer store with four thousand dollars, and emerge bow legged, carrying a bulky notebook computer the size of a sewing machine - about as cutting edge as grandpa's pipe and smoking jacket. Today you can pick up a Compaq NX6125 from HP, equipped with a biometric fingerprint reader, 60GB hard drive, and an AMD 64 bit Turion processor for less than $1000!

Expect prices for laptops to get even lower in the coming months thanks to intense competition between the two heavyweight processor manufacturers, Intel and AMD. Both companies have introduced mobile chips with speeds that offer desktop performance.

CONNECTIVITY

Laptops with Wi-Fi are no longer an optional luxury. At Mammoth Coffee in Newport, Ohio, more and more business owners are jostling for notebook "office space", - to the modest tune of a blueberry muffin, and a Cafe Au Lait.

Those who dine at fine restaurants at the very least expect a sensory, savory meal, set upon a table with fine silver and white table cloths; superior service; and ambient lighting. Well that's exactly what's on the menu at Trapeze restaurant in Burlingame, California,- along with wireless access service for laptops.

Wireless fidelity has moved effortlessly from the boundaries of home and office to the pristine elegance of posh restaurants. But, will the wireless laptop revolution end here?

Last Mile Communications have even greater ambitions for Wi-Fi notebooks. They hope to use the established infrastructure of the many lamp-posts dotting around merry old England to produce a network of wireless access points.

This ambitious UK company would like convert the street lights so they can be accessed via your laptop to get on the internet. Last mile would also like to put flash memory in the lights so even without accessing the web you could find information about local amenities, and emergency fire, police and ambulance services.

PORTABILITY

Laptops with performance rivalling that of desktop computers used to be knee breakers - Not any more. A stream of high quality ultralights and ultraportables have flooded onto the market in the last few months.

Acer's Red dot award winner,the Travelmate 3000 boasts a widescreen 12.1 inch panoramic display, and the notebook's compact chassis occupies less desktop space than a sheet of A4 paper - weighing just 1.4kg. The Sony T2, a sleek silver ultralight laptop, is equipped with a 60GB hard drive, 1.2GHz processor and weighs just under 1.4kg.

Too big you say? How about Toshiba's Libretto U100? This laptop weighs just 2.16 pounds, has a 1.20GHz Intel Pentium M processor, and sports a hard drive protection system.

Tom Fox writes for the <a target="_new" href="http://www.laptopical.com">Laptops Weblog</a> - Laptopical is a site dedicated to offering relevant news commentary and reviews about notebook computers.

More <a target="_new" href="http://www.laptopical.com/site-map.html">laptop news</a>

A Guide to Refurbished IBM Laptops

IBM boasts a very large array of older and newer refurbished laptops on their website ibm.com. Look for &quot;Notebooks: IBM Certified Used Equipment.&quot; There you can buy any of dozens of models and variations, for hundreds of dollars less than new models. IBM inspects all of their returned laptops (including the batteries, as with most factory-refurbished laptops), makes sure they up and running at top speed, and repackages them for resale.

Most IBM refurbished laptops are ThinkPad A-series or T-series. A-series are heavier, but much more powerful, since they are designed to replace desktop computers. They can handle everything your desktop computer used to handle, plus they fit in your laptop carrying case. A-series models are generally more expensive than those in the T-series.

IBM T-series notebooks are made to be a little more powerful and a lot lighter and smaller than the A-series models. They were introduced to satiate those who were demanding a more portable model, so they could take all of their work with them wherever they went. Since they are a newer series, and because they are starting to replace the A-series, the T-series models are a bit more expensive.

As with most laptops refurbishing factories, IBM offers a three-month warranty and guarantee on all of their refurbished laptops ? including for the battery. Third-party refurbishers also offer a ninety-day warranty, but with no warranty on the battery.

<a target="_new" href="http://www.i-refurbishedlaptops.com">Refurbished Laptops Info</a> provides detailed information on quality, cheap refurbished laptops by manufacturers like Dell, IBM, Toshiba, and HP, as well as refurbished laptop batteries and related products. Refurbished Laptops Info is the sister site of <a target="_new" href="http://www.e-rackmountcomputer.com">Rack Mount Computers Web</a>.

ESR Meter - The Capabilities To Check Beyond Electrolytic Capacitor

There is something good about esr meter because besides electrolytic capacitor it can be use to measure other type of capacitors such as the non polarity capacitor. From esr meter specification, it is usually mentioned only checking the electrolytic type. When i began to experiment with the Dick Smith ESR Meter i found that it have the capabilities to check other type of capacitors as well.

However it is limited to checking capacitor in the higher value only such as .1uf(104), .22uf(224), 1uf(105) and etc. Lower capacitance value don't get any reading from the esr meter due to it can only read until 99 ohms. Perhaps other esr meter such as the B & K esr meter have the range to check it.

You will even be surprised to see that the dick smith esr meter can check the non-polarity capacitor in-circuit (without removing the cap).

True case example-Monitor came in with display jumping horizontally. You can see a bunch of horizontal black lines across the top display (picture). From experienced it will tell you that vertical section have problem. I begin to troubleshoot the vertical section. Supply voltage checked ok, vertical driver and oscillator IC replaced, all components connected or nearby vertical driver and oscillator ic have been checked ok. By the way I used digital capacitance meter to check the non-polarity cap and esr meter to check the electrolytic cap. The problem is still there and can't be solve!

When i use Dick Smith ESR Meter to compare the esr value of a non-polarity capacitor located near the vertical driver ic, i noticed that there is a big different in the esr value. The good esr value for a .22uf non-polarity cap is between 6.5 to 7 ohm but the spoilt one have a value of 14 ohm! Almost double the value, that's why the display jump. The good thing is i discovered the culprit while the capacitor still in the circuit which mean this esr meter can check non-polarity cap in-circuit. However my recommendation for you is to solder out one leg and check unless you already have the experienced in checking components on board. Replacing the cap solved the display problem.

Conclusion-In order to accurately test a non-polarity capacitor, besides checking the capacitance value and using analog meter to check the charge and discharge to see if it has develop any short circuit when under load, you are also required to check the esr value as well.

Jestine Yong is a electronic repairer and a writer. For more information about electronic repair please visit his website at <a target="_new" href="http://www.noahtec.com/electronic-repair-articles.htm">http://www.noahtec.com/electronic-repair-articles.htm</a>

How to Read CRT Tube Part Numbers

All picture tubes, whether monochrome or color type are identified by a specific code consisting of numbers and letters. The codes are different from each other because different tubes have different characteristics.

For example, a certain monitor colour picture tube may have the designation, M34AFA63X03 that can breakdown into 6 parts: M/34/AFA/63/X/03

Part 1: Application

Computer monitor tubes start with the letter "M&quot; while for a TV picture tube, it start with &quot;A&quot;.

Part 2: Screen diagonal measure in centimeters (cm)

The &quot;34&quot; means the diagonal viewing measure is a minimum of 34cm which refers to 14&quot; tube, 36cm is 15&quot;, 41cm is 17&quot; and so on.

Part 3: Family code

The three letters &quot;AFA&quot; designate a family of tubes that have similar physical and electrical characteristic. These letters are assigned alphabetically beginning with &quot;AAA&quot;, followed by &quot;AAB&quot;, &quot;AAC&quot; etc.

Part 4: Family number

The number 63 shows a specific tube within the family code. A different number is assigned to tubes within the same family that have different neck diameters, for example a single digit would be a monochrome tube, but this two-digit number shows it is colour.

Part 5: Phosphor Type

The fifth symbol gives the phosphor designation. The letter X here corresponds to P22 for colour picture tubes. Colour monitor tubes can have any other single letter (excluding I, O, or W) to designate other phosphor type for various applications. For monochrome pictures, the phosphor symbol is WW, corresponding to P4. Monochrome monitor tubes also can use WW or some other two-letter combination (excluding I and O).

Part 6: Integral neck components

The sixth symbol is assigned only for tubes having integral neck components, such as the deflection yoke. The specs are only apply to a particular tube manufacturer. The primary consideration here is winding inductance. The yoke coils have different sensitivity i.e. deflection per Amp in both horizontal and vertical.

Jestine Yong is a electronic repairer and writer. For more information about electronic repair please visit his website at <a target="_new" href="http://www.noahtec.com">http://www.noahtec.com</a>

A Guide to Refurbished Laptops

Computing freedom, independence, and mobility don't have to come with a hefty price tag.

Manufacturers refurbish laptop computers that have been returned. The laptop might have a scratched screen or other minor blemish. In some cases, the laptop was an unwanted gift or its packaging was dented. The laptop is inspected by the manufacturer, tested for quality, and repackaged for sale at a much lower price.

While many new laptops can cost thousands of dollars, most refurbished laptop computers usually cost less than a couple of grand, and often less than $500. In most cases, they are as good as new and have a very low return rate. They even come with guarantees and warranties, just as you would expect with a new model.

A refurbished laptop can satisfy most people's basic computing needs, such as word processing, running software, reading e-mail, creating spreadsheets, playing CDs, surfing the Internet, and more. Laptops allow access to all these features from anywhere.

All laptop manufacturers offer refurbished laptops, including such popular brands as Dell, IBM, Toshiba, and HP.

Computer prices are affected by type of processor, operating system, modem, and network card; size of the hard drive and RAM (Random Access Memory); and whether there is a CD/DVD-ROM/RW, a video card, a sound card, and zip drive. Prices are also affected by screen size and type of chassis.

The price will be affected by all these specifications, along with how well preserved the chassis is, the name of the manufacturer, and whether you acquire the laptop form the factory or through a private dealer. Private dealers charge less, but beware: not all dealers are up to par with their refurbishing skills. Be sure to go to one that is reputable and experienced.

<a target="_new" href="http://www.i-refurbishedlaptops.com">Refurbished Laptops Info</a> provides detailed information on quality, cheap refurbished laptops by manufacturers like Dell, IBM, Toshiba, and HP, as well as refurbished laptop batteries and related products. Refurbished Laptops Info is the sister site of <a target="_new" href="http://www.e-rackmountcomputer.com">Rack Mount Computers Web</a>.

How To Purchase A Quality Laptop Computers Case

So you finally have that new laptop you have been drooling over for the past 3 months, only there is one problem ?- You don't have a case for it. You've probably already laid down over a grand for the notebook and you're telling yourself that you don't want to spend another $70 for a case. Trust me, this isn't the time to be cheap.

In this article I will go over the importance of getting a quality notebook bag, as well as what sort of features are found on quality laptop cases.

If you consider your laptop to be important or essential, then getting a good, solid case is a must. You may be wondering why? Here are just a few reasons:

- Expensive notebook should be protected properly
- Quality cases have way better outer and inner protection for your laptop
- More comfortable
- Better shoulder protection

If you still need some prodding in the direction of that super duty case maybe the next points will help. Let's go over what distinguishes the good from the bad in notebook bags.

Comfort ? Quality bags have much better shoulder support than cheapies. Your notebook is going to be at least 6 pounds, probably more. Do you really want to break your shoulder just carrying the thing around? You have a lot more choice with quality aftermarket cases as well when it comes to carrying style. In the end you are going to be a lot more comfortable with something that wears well on you.

Protection ? Make sure you don't drop that notebook case that came with your computer ?- You may find your laptop in pieces. Quality laptop cases have great inner and outer protection. Things like reinforced corners on the outside, and air pockets on the inside? It all adds up to piece of mind. If you want, you can even find cases with single or double combo locks.

Storage ? If you want to put extra files or folders into your notebook case you are going to need the space. Quite often, cheaper cases will have just enough room for a notebook and maybe a small folder if you are lucky. When buying an aftermarket case you have a lot more choice in size, and can find something that will hold everything you need it to.

Are you ready to spend a little more money and get that quality case now? Good, but before you do, let's go over a couple more things that are very important.

First, you need to think about what you will be carrying most of the time -- Chances are it isn't just your laptop. What you will be carrying will be a big part of what case you decide on. The more stuff you need to bring along in the bag, the bigger the bag needs to be.

Next, find out the dimensions of your notebook. You need to know this when buying a case. Not all laptops fit in every case, so you need to look for a case that will fit the size of your notebook. Whether you are buying a case locally or online, the main compartment size of the case should be easy enough to find.

Lastly, as you will soon find, there is more than one style of laptop case available. There are the standard cases, ones that look like actual luggage bags, and even backpack style cases. The last one has the added benefit that thieves won't think there is a notebook sitting inside.

Going over exactly what you need in a laptop case, and then purchasing a quality one won't just save your shoulders in time, but possibly your investment too.

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Cody Kahl is creator and writer of Toshiba Laptops Guide ? A site
dedicated to providing only the best <a target="_new" href="http://www.toshibalaptopsguide.com/toshiba-laptop-computers.html">toshiba laptop computers</a> information.
Cody believes in quality, and this free resource proves it.
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Ceramic Disc Capacitor-How to Accurately Test It

The last article I mentioned about electrolytic capacitor breakdown when under load. In this article I will talk about the high voltage resin coated ceramic disc capacitor. In computer monitor, it is frequent used in the screen voltage (G2) line at the crt board. When it fails, it can cause erratic or intermittently raster bright and dim and sometimes no display.

Adjusting the flyback transformer screen control will not solve this problem. You can isolate the problem as whether if it cause by a defective fly back or G2 line at crt board. Remove the G2 wire from circuit and measure the screen voltage with a digital multimeter- it should have a constant voltage (will not vary). If the voltage is not stable suspect the fly back. If it ok then trace the screen voltage circuit. Usually this circuit consist of only resistors and capacitors. Sometimes a defective crt socket might cause this type of problem also!

Many times a tech can't solve this intermittent or no display problem is because their digital capacitance and ohmmeter measured ok on the capacitors. The capacitors in the screen voltage line are usually rated of 102,103, and 472 1kv to 2kv. A 'missed' in checking this capacitors will caused the technician can't solve the problem, unless he direct replace the capacitor. An intermittent capacitor can pull down the screen voltage causing the display problem.

As mentioned earlier, an ohmmeter with 12v output and a digital capacitance with 3v output are unable to accurately check the capacitor that have the rating of 1-2 kilovolt!

If you have the analog insulation tester or meter, the panel will show a short circuit when certain voltage are pump in to check the high voltage capacitor. The voltages that you can select is depends on the brand or model you buy. Some have the range of 50v to 1000v and some have the range from 100v to 500v. It is optional whether you should have one. If you have one then it would be an added advantage for you. The other option that you have is to direct replace the suspected capacitor. In my country, you can get a new one in less than US150.00 or you may bid a used unit from eBay.

As for me, checking the small blue resin coated ceramic disc capacitor that have the capacitor code of 104 50v, besides using digital capacitance meter to check for the value, i also use an analog meter set to times 10Kohm that have the output of 12v to check this type of capacitor. Many times it will revealed the bad intermittent capacitor. You will be shocked to see the capacitance meter checked ok but show a shorted reading when check with analog multimeter.

In the market there is certain brand of analog multimeter that have the range of 100kohm. If you open up the cover, you can't see the 9v battery in it, what you see only the 2 pieces of 1.5v battery. This type of meter can't accurately detect the short in the capacitor because the output voltage is only 3volt!

For those of you who involved in repairing monitor, you will agree with me that checking the flyback internal capacitance- quite often you get the right value 2.7nf with digital capacitance meter but when you switch on the monitor, you will hear a 'tick-tick' sound from the flyback. This is because the capacitor is breaking down when under load. If you did not do anything with the flyback, gradually the internal capacitance will become shorted and you will need to refurbish the flyback.

Jestine Yong is a electronic repairer and a writer. For more electronic repair information please visit his website at <a target="_new" href="http://www.noahtec.com/electronic-repair-articles.htm">http://www.noahtec.com/electronic-repair-articles.htm</a>