Every graphic card carries a graphic chip (GPU) and very fast DDR RAM for textures and 3D data. Their data buses have 1X, 2X, 4X, and 8X speeds. The bus is 32-bit, much like PCI.

AGP slots are slightly shorter than PCI slots and often brown in color. A similar type of slot called AGP Pro is longer and has extra power leads to accommodate modern video cards. It didn’t really catch on in the mainstream market, and graphics card makers preferred to add an extra power connector to supply the power they needed.

The specification features:

• Plug and play configuration (through standardised means for interacting with configuration software)
• Standardised electrical connections

Common PCI implementations in desktop PCs feature:

• 32-bit addressing
• 33-MHz bus clock

High-end implementations may also feature:

• 64-bit addressing
• “Hot plugging” (the ability to add / remove PCI devices from a running machine)
• 66-MHz bus clock

(all of these are characteristic of PCI-X)

There have been many revisions and evolutions of the PCI specification over the years. Recently, PCI-X has sought to extend the aging architecture for the needs of modern server-class machines, avoiding some of the performance bottlenecks of previous revisions. The new PCI Express specification seems likely to succeed PCI in all classes of personal computer within the next few years.

The reason for the change is that the older PCI cards don’t transfer data quickly enough to keep up with modern day gaming, autocad and video editing software.

Think of it this way, there is a tap that is two inches in diameter, but a drain that is only one inch in diameter. the water doesn’t drain quickly enough and eventually the sink overflows. Just like a PCI video card.

Some of the types of RAM are SDRAM, DDR RAM, Rambus RAM, SIMM, DIMM.

The Motherboard also holds things like the BIOS (Basic Input Output System) and the CMOS Battery (a coin cell that keeps an embbeded RAM in the motherboard -often NVRAM- powered to keep various settings in effect).

Most modern motherboards have onboard sound and LAN controller, some of them even have on-board graphics. These are adequate for standard office work and system sounds. But dedicated sound and graphics cards plugged into the expansion slots offer much better quality and performance

The expansion slots (PCI, PCI-e, PCI-X, AGP, ISA, etc.) allow additional functions.

There will be a bunch of connectors coming off of the supply, called Molex connectors. They come in varying sizes, meant for different applications, such as the motherboard (usually the largest of the connectors), the hard and optical drives (a bunch of medium-sized connectors), as well as the floppy drive (a relatively small connector, also saw usage among videocards in 2004). As newer standards come out, the types of connectors have changed. Many power supplies now come with power connectors for Serial ATA hard drives. These are smaller and are “hot-swappable”, meaning they can be removed and plugged in again without fear of data loss or electrical problems.

The power supply also has an exhaust fan that is responsible for cooling the power supply, as well as providing a hot air exhaust for the entire case. Some power supplies have two fans to promote this effect.

It is important to buy a power supply that can accommodate all of the components involved. Some may argue that it is the most important part of a computer, and therefore it is worth spending the money to get a decent one.

The Mini-ITX is much different in important ways unlike its relatives the Micro-ATX and the Flex-ATX. The mainboard size can be up to 170mm x 170 mm which is smaller than the Flex and Micro-ATX can be. Usually at less than 100 watts, the Mini-ITX PSU is energy efficient. The Mini-ITX is also backward-compatible with the Flex/Micro-ATX models.

During the 1980’s and 1990’s almost all cases were beige, even Apple’s Macintosh line. A few rare exceptions to this were black. Only recently have computer case designers realized that there was a worthwhile market for other colors and designs. This has led to all sorts of modifications to the basic design of a computer case. Now it is easy to find cases with transparent windows and glowing lights illuminating their insides.

It’s typically a square ceramic package plugged into the motherboard, with a large heat sink on top (and often a fan on top of that heat sink).

All instructions the computer will process are processed by the CPU. There are many “CPU architectures”, each of which has its own characteristics and trade-offs. The dominant CPU architectures used in personal computing are x86 and PowerPC. x86 is easily the most popular processor for this class of machine (the dominant manufacturers of x86 CPUs are Intel and AMD). The other architechtures are used, for istance, in workstations, servers or embedded systems CPUs contain a small amount of static RAM (SRAM) called a cache. Some processors have two or three levels of cache, containing as much as several megabytes of memory.

Dual Core

Some of the new processors made by Intel and AMD are Dual core. The Intel designation for dual core are “Pentium D”, “Core Duo” and “Core 2 Duo” while AMD has its “X2″ series and “FX-6x”.

The core is where the data is processed and turned into commands directed at the rest of the computer. Having two cores increases the data flow into the processor and the command flow out of the processor potentially doubling the processing power, but the increased performance is only visible with multithreaded applications and heavy multitasking.

Hyper Threading

Hyper Threading is a technology that uses one core but adds a virtual processor to an additional thread at the same time.

Normally the processor carries out one task and then proceeds onto the next task. But with Hyper Threading the processor continually switches in-between each task as if to do them at the same time.

For more information, consult the Wikipedia article on microprocessors.

Are these terms familiar to you? Monitor, RAM, CD drive, CPU, graphic cards are all hardware, or more accurately, computer hardware. These components make up a computer, working together with computer software to make a computer work.

Simply put, hardware is the tangible parts of your computer, parts you can touch, feel and so on.

Hardware Failures

As mentioned before, hardware and software work together to form a fully functional system, theoretically. However, rarely do you get a fully functional system all the time. There will almost certainly be malfunction of hardware, be it within the electronic circuits or even the whole component itself. Sometimes, the originating factor of the hardware failure is not the components of the system itself, but due to outside factors such as environmental disasters like fire, earthquakes and lightning storm.

Recovery of failed hardware components is not a big problem by itself. It is basically identifying and replacing the problematic component. However, hardware failures are most deadly, when it affects daily routine and affecting critical personal or business data. This is especially true of the most important component of a computer system when it comes to storage of data, the hard disk.

The following is a list of common hardware failures:

• RAM Failures
• Power Connector
• Hard Disk
• Overheating
• LCD Failures
• Motherboard
• USB Box

RAM Failures

Bad RAM is somehow harder to diagnose as similar symptoms may be caused by software problems, other hardware problems or even motherboard failure. However if you experience any of these symptoms, users should check for bad RAM before attempting any other troubleshooting.

Symptoms:

• Windows doesn’t start showing different error messages each time.
• Windows crashes (blue screen) or freezes frequently.
• Windows crashes as soon as you try to start a program.
• Unexplained random crashes and freezes without error messages.

Power Adaptor

The common weak spot on any laptop is the DC power jack. If someone trips over the power adapter cable while it is still connected to the laptop, there is a high possibility that the power jack will get severely damaged.

On most laptops, the DC power jack is soldered directly to the motherboard and there are only three or four small pins holding it in place, which makes the power jack rather weak. Any sideways pulling of the DC power cord while attached to the laptop will usually dislodge at least one of these pins, breaking the solder around it. Modern laptops use quite a lot of power, from about 70W to 120W or even more. The bad electrical connection from the dislodged pin will cause sparks and heating that will eventually burn a hole through the motherboard and can even be a fire hazard.

Symptoms which indicates poor contact between the DC power jack and the motherboard:

• The battery is not charging properly or stays at half charge despite having to use the power adaptor.
• The screen flickers (the brightness is changing) while the power cord is plugged in. This is caused by the laptop switching between DC power (screen is brighter) and battery power (screen is dimmer).
• The DC plug gets hot after a few minutes of use and may even smell of burning.
• There are “scratching” sounds coming from the DC jack.

How to test for broken power jack:

1. Remove the battery
2. Plug in the power cord
3. Start the laptop
4. Gently wiggle the DC power plug on the back of the laptop

If the laptop shuts down abruptly (looses power), find the dealer to re-solder or change the DC power jack as soon as possible as the motherboard has already started to burn around the dislodged pins. The manufacturer might offer to replace the whole motherboard; however the price of a new motherboard together with the labor charge for installing it will usually cost more than the current value of that laptop and sometimes can the pricing can cost over a thousand dollars.

Replacing or re-soldering the DC power jack is not an easy job. It usually takes a few hours depending on the damage and the model of the laptop. To reach the power jack, the laptop has to be completely disassembled and have the motherboard taken out. Then if the board around the dislodged pin is badly burned, the power jack has to be un-soldered and the board has to be patched.

After that a different power jack has to be installed, attached to the case of the laptop and connected with wires to the motherboard, as the patched board wouldn’t be strong enough to support the original type of power jack that was soldered directly to the board.

Hard Disk

Hard disk failures are the most common computer hardware problems. And laptop hard disks fail more often than desktop hard disks due to the portability of a laptop as compared to the rather stagnant laptop. If user knock hard or drop the laptop even a few inches while the hard disk is being accessed or powered up, damage can be done to the hard disk.

Symptoms:

• The laptop starts as usual but when Windows starts to load it goes to blue screen with either “UNMOUNTABLE_BOOT_VOLUME”, “hal.dll is missing or corrupt” or “WINDOWSSYSTEM32CONFIGSYSTEM” (or similar) is missing or corrupt. All these error messages indicate a file system problem. Sometimes it can be fixed by just scanning the hard disk for errors. However more than half of these cases indicate that the hard disk is starting to go bad and is probably developing bad sectors.
• The laptop starts as usual but Windows freezes on the initial “Windows XP” screen, although the blue bar continues to move, and users are able to hear feint but continuous clicking. Hard disks have to be replaced.
• As soon as the laptop is started there are loud clicks or grinding sounds and Windows doesn’t load. Hard disks have to be replaced as well.
• Shortly after starting the laptop a message appears (usually on a black screen) “SMART test failed. Backup your data immediately and replace the hard disk” or similar. Well, that says it all. S.M.A.R.T. is a self-test that is build into the hard disk.

In almost all cases the laptop can be started from a “live” bootable CD and everything works normal. In rare cases the hard disk PCB (printed circuit board) may get short circuited and even burn. In this scenario, the laptop won’t start unless the hard disk is removed.

A good tool to use to check for hard disk lifespan is ADRC’s hard disk checker. It will scan the hard disk for bad sectors and inform you if the drive is still of good usability.

Overheating

Overheating happens when inadequate airflow from outside the computer’s case across the CPU and motherboard and back out of the case usually via the power supply fan and other case fans.

Once the airflow is disrupted, heat builds up rapidly within the case. This causes components to either shutdown, if such protection is built in or performs erratically. Over the long term, overheating can irreversible damage components.

It is also advisable to keep the computer in a dry and shaded room, which is clean and little dust.

LCD Failures

The most common LCD or “Liquid Crystal Display” screen failure is the inverter, cable and backlight.

Symptoms:

• The laptop appears to start as usual but the screen is black, if users move it, it turns on and works properly. Failed cable.
• The laptop appears to start as usual but the screen is very dark, although it changes colour a little and users can see a very feint image. Failed inverter or cable 90%/10%.
• Immediately after starting the screen has dark pink/red tint and turns dark after a few seconds. Failed backlight.
• The screen flickers a few times but then turns dark, if users move it or tap it lightly on the sides, it flickers again. Failed cable or LCD 50%/50%.
• Screen is either black or white (no picture) and external monitor works. Failed cable or LCD 30%/70%.
• There are stripes on the screen (either vertical or horizontal) that change when users move the screen or tap it lightly on the sides. Failed cable or LCD 10%/90%.

Motherboard

Most motherboard related failures are due to the “On-board” regulated supplies and component failure within those circuits. The on-board power supply circuit had partially failed and was overloading subsequent components else the problem would be with the capacitors which are defective in the first place.

A motherboard failure on a laptop that is out of warranty would usually mean that it’s time for a new laptop. The price of a new motherboard is usually higher than the current value of the laptop.

Symptoms:

Plug in the power adaptor and try to start the laptop.

• Nothing happens.
• The “ON” light comes on, the fan spins, but nothing on the screen (black) and you can’t hear the HD working after 10-15 sec.
• The “ON” light comes on, the fan spins, but after a few seconds the light goes off.
• After pressing the “ON” button the screen stays black and you can hear a quiet high-pitched sound coming from the laptop.

Corrupted or improper device drivers and operating system

Invalid or corrupt device drivers can wreck havoc on a server, rendering the system unbootable in some cases. Device drivers may also conflict with certain application programs and cause problems with the computer system.

As Windows Vista has just made its launch, chances are some hardware is not supported or not supported fully by the new operating system.

Also, system updates, driver updates can also fix your “hardware” problems.

See updating and fixes

Also, it helps (occasionally) to call the respective support service for help on the driver that is with that particular hardware.

Controller Failure:

A controller failure can act much like a drive failure. However, when a drive fails, users cannot access that particular drive; when a controller fails, users cannot get access to all the drives, devices and any other components that is attached to that particular controller.

A controller fails because a component or components on the on the controller board fails. When users trying to boot the system, they cannot switch on, view, access, or even get hardware conflict messages.

Controller failure occurs due to one of the following reasons:

• Devices/components not connected properly
  Verify that the cables are properly connecting the device /component to the controller
  If the component fits into a slot, see that the it is flushed in and not loosely connected.
• Devices/components not setup properly
  Verify that the devices/components is being properly detected and setup in the respective controller setup screen
• Bad connectors
  Replace the bad connectors with new working ones
• Bad components
  Replace the component
• Bad interface board or motherboard
  It is recommended that these components be replaced or that the computer be sent in for servicing

Hardware Failure: The big issue

The big problem, as mentioned earlier, is not replacing or repairing the non-functional hardware, but the time lost, interruptions to daily routine (especially for businesses), and the loss of critical data. If you need a running system at all times, have a backup system as a fail safe, or even two. If users want to ensure that none of their critical data is lost in the event of a hardware problem with their computer, there is only one way to do it — Back up the data as often as possible.

There are many different ways to ensure that the data is backed up, and as technology becomes advances, back up methods become much simpler.

Let’s look for a moment at what a back up is. Backing up of computer files means that users are making a copy of the data that will be stored somewhere other than on the computer. Everyone should always have a back up of at least the most important files, because should anyone experience a hardware problem, they could still be able to access the files.

Many people don’t back up their files, because they don’t know what they need to back up. Start with those files that cannot easily be recreated. Then, move on to files to which you make frequent changes just in case you accidentally change something that you shouldn’t have. Back up your music collection – because this can be quite expensive to replace in the event of data loss.

In general, best practice is to back up the files at least monthly and more frequently if users access the files regularly.

Chee Ning is currently employed as a web administrator and support staff, at Adroit Data Recovery Centre’s laboratory, which is located in Singapore’s Science Hub.

With the necessary tools, parts and experience, ADRC strives to spread the word about data recovery, and help people recover data which means so much to them. – Adroit Data Recovery Centre Pte Ltd