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Computer memory can fail as with any other electronic device. The computer memory problems are very rare but it happens sometimes.
The failing memory symptoms include computer locking or crashing. Blue screens are rare when the memory fails. And, there could be no indication whatsoever as to a RAM problem until the OS reaches the faulty cell and then crashes. For example, if the faulty cell is at 1.8 GB. The operating system Windows XP usually takes about 1 GB of memory. And, the fault will not be seen for a while.
Computer memory problems also can be identified by running Windows operating system setup. For example, the Windows XP setup consists of checking the file consistency on the hard drive, and it will display a warning message if the files are corrupt.
Faulty memory cells
You will find many different applications to check the memory of your computer. One way you can do this is by using an application known as MemTest. This program checks computer memory for any defects and then shows the speed of the processor. It also shows the type of memory it is analyzing.
Figure 1: A classic example of RAM fault. In red are marked bad cells.
To start with, you will need to burn the application on a CD drive. When you are done, this CD becomes a bootable disk. You can boot your computer with this disk and the test will start automatically.
The rest will continue on autopilot. Allow the application at least an hour within which time it will conduct all the tests it wants to perform on your computer. It will find out about the speed of your processor, the speed of the RAM and what type it is, as well as the speed of the bus and the cache on your computer’s processor.
You will get a message detailing this information. If any kind of fault is found, such as a defective RAM, a warning in red will be displayed.
You can also get the memory modules from your laptop computer and then check out the manufacturer’s labels that are printed on them. But, do not count on this too much, because the labels may not always be there. And, even if the labels are there, it is not necessary that you will always find the memory printed on them. For that, you will be required to find the capacity of one memory chip, and then use a little math to multiply it with the total number of memory modules that you have. Or, use MemTest for this purpose.
This is not a widely known phenomenon; this happens when the same speed memory modules perform operations in different speeds. I would explain this as a varying length of the tracks that connect memory chips, and the different topology inside the tracks. At speeds 1 GHz and more, the track length starts to influence how long it will take signals to reach the destination. In previous memory modules like SDRAM, SIMM, there was no such problem.
To avoid this, use modules of the same speed and of the same manufacturer. Even better would be to compare them alongside one another and make sure the chips are identical and the track topology on the PCB is identical. The memory modules should look like clones.
Faulty memory banks
Usually this happens when the motherboard gets physically damaged or there is a manufacturing fault that happens on the North Bridge BGA or somewhere in the CPU socket soldering. This can be identified by taking out one memory module and then running MemTest. Sometimes the computer does not even start if there is a memory module in a faulty bank.
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Me holding a laptop hard drive