My computer will not turn on. Absolutely nothing happens. So I thought it might be the psu. I have now changed from the origrinal 300w to a 420w trust psu. When I connect only the 24pin connector it powers on the fans etc but also have a VERY loud beep tone. Its a constant sound, not beeping or anything.
If I connect both the 24 and the 4pin 12v connector, nothings happens.
Was your original pc a dell or similar prebuild?
list what you can for us please partswise
you can try the paperclip test on the psu's, but that only shows it fires up, not how it holds up under load
Ok, thats not too bad then, Dull and some other builders swap wires around so you can't swap psu's,
Try the gfx card in another pc, to check it works,
try the psu powering same pc,
try putting one stick of the offending systems ram in the good pc (assuming same ram is used in both systems) and trying to boot, if it wont boot stick is bad obviously, check all sticks
might be worth reseating the heatsink depending how long its been on there as well but try the other stuff first to rule out them being the issue