Some of the techniques adopted to isolate possible memory problems are as follows:
Removing the modules
One of the most common methods of isolating an erring memory module is moving the modules and swapping them between slots on the motherboard. If your motherboard uses "SIMM" modules, the slots must be filled in pairs. If your motherboard has "DIMM" memory modules, and you have 2, then you can remove one, run the tests and then swap it for the one removed.
In this manner you would be able to do away with the bad module quickly. Take note of modules that pass or fail and then switch that one with the other.
Swapping
In case if you have two memory modules, you can swap and rotate modules to determine the defective one. You should change the location of two modules one at a time and run the diagnostic test. When the failing data bit or address changes, you are able to find out that one of the modules you have swapped recently is failing. If you are able to start up the system successfully with the first combination, and after swapping the PC does not boot, then the module in slot zero is the defective one. Thus by using combinations of module swapping, you can find out the defective ones.
Replacing modules
If the above methods do not help to pinpoint the defective modules, you can either swap them with known good modules or send them to a testing facility. You can use known good modules and replace one module at a time to pinpoint the memory failure.
Removing and Cleaning metal contacts
In case of older systems, dust or oxidation may result into poor contact in the SIMM/DIMM slot. You should clean the gold or tin contact by removing the module. Ensure that you are not reversing the module while reinserting into SIMM/DIMM slot after cleaning.
Using the motherboards BIOS beep codes
BIOS emits beeping sound from built in speaker on the motherboard to inform you about the problems that your system is having. The most common beep tones are as follows:
1 Beep tone - DRAM refresh failure
2 Beep tone - DRAM Parity failure
3 Beep tone - Base 64K RAM failure
4 Beep tone - System timer error
5 Beep tone - CPU failure
6 Beep tone - Keyboard controller error
7 Beep tone - Virtual mode error
8 Beep tone - Display memory read/write error
9 Beep tone - ROM BIOS checksum error
10 Beep tone - CMOS register read/write error
11 Beep tone - Cache memory error
Continuous Beep tone - Memory or Video memory failures
