Which of the 4 memory modules is defective?

4, 2, I’ve got you! – finding the defective module quickly and easily

This is the situation:
– I have 4 memory modules installed
– The system will not run or even boot up, which may indicate that memory is defective.

The problem:
Which module is defective? At first glance, it would seem to be a hard problem to solve. To find the defective module many experts will recommend cross swapping or individual testing. Most users find this process time consuming and costly – a valid complaint as you have to install each module up to 4 times and then wait for the system to boot up – or not, as the case may be. This process will often cause additional damage (e.g. through ESD). And everyone knows how Murphy’s Law likes to rear its ugly head.

The CompuRAM method will allow you to find out which of the 4 modules is defective within 2 system restarts. This is not only faster but minimises the risk of damaging your system.

This is how it works:
All you need is your system with the memory modules A, B, C and D.
The following sketch will illustrate the process.

Step 1: Install modules A and B and boot the system.

Result a):
System runs smoothly, memory test indicates no errors.
Proceed to step 2a!

Result b):
System crashes or refuses to boot, memory test finds an error. One or both of the modules is/are defective.
Proceed to step 2b!

Step 2a:
Install modules A and C and boot the system.

Result a):
System runs smoothly, memory test indicates no errors.
> Module D is defective!

Modules A, B and C are error free.

Result b):
System crashes or refuses the boot, memory test finds an error.
> Module C is defective!

Module A has already been tested and was OK!

Step 2b:

Modules A and D are installed and the system booted.

Result a):
System runs smoothly, memory test indicates no errors.
> Module B is defective!

Modules A and C both work and we can assume module D is also operational.

Result b):
System crashes or refuses to boot, memory test finds an error.
> Module A is defective!

Problems also occured with the A/B test. We can assume module D is error free.

Tags: RAM test, Troubleshooting