What if the chips are all good but my PC won't recognise them?
If you're unable to isolate a bad chip, it could be that the socket, not the chip, is at fault. Occasionally, a bit of fluff can get stuck inside the RAM socket and affect the connection to the module.
Get a can of compressed air (available at most computer and office supply stores). Turn off the computer, open the case, remove your RAM modules, and then blast out any debris from the socket. Then, reseat your RAM and power up your PC. If that didn't do the trick and you have another PC at your disposal, try testing your RAM in that one, following the steps above.
If you don't have another PC, take your RAM back to where you got it (or to any computer repair shop) to be tested. If it passes, then it's likely that your RAM socket is burnt out and will need to be replaced.
