PC switching off after a few secs

[mecca2010]

I have an old Fujistu pc. Recently when i went to switch it on it started booting up but 3-4 seconds later just switched itself off. The only way I can keep it on is if I remove both RAM cards, so I know the PSU must be ok but Im reluctant to think both cards have failed so my next guess is the motherboard. Anyone have any ideas. Thanks

[Match]

The only way I can keep it on is if I remove both RAM cards

 

Have you tried replacing one then removing it and replacing the other one?

 

also have you tried resetting the cmos, there should be a jumper on the motherboard, but if not simply remove the battery for around 30Secs.

 

also if you can get into the Bios it still might be worth checking that all the Voltages are holding stable, just because the PC starts without the RAM doesn't mean that you have a Good PSU as by removing the RAM you are lowering the Power needed at start up.

 

also with the RAM in when you boot the PC does it POST OK or are you getting a BEEP code before it shuts down?