I haved a Dell Dimension that I bought new. It was working fine until one day it wouldn't turn on.
I checked all the normal things like power cord, different outlet, taking out any cards and disconnecting the power to hard drive and DVD rom. I left the RAM in and it wouldn't power on.
It basically starts to turn on but shuts right off just a split second after the CPU fan turns on.
THen I took all the 4 ram modules. Now after turning it on, it stays on but just beeps (obviously not passing POST because no memory is found).
I tried the ram (which has to be installed in pairs) in the different slots and when the RAM is in, it won't turn on, but when no RAM is installed, then it powers up.
I do have the green light on the MB no matter if RAM is installed or not.
I initally called DELL and was told the Power Supply was likely shot. SO I have already tried a new power supply and that didn't change anything.
ANy ideas ... I'm thinking the MB has bad RAM slots or something.