Hey there, I built a PC for a friend about a year ago, and recently it stopped putting out any video signal a short while back. I'm not able to find out if there was any software changes prior to this but basically I tested his PC out with my GFX card, and there was still no video signal output (his GFX card worked on my PC fine). Next he sent all the parts back to the vendor, they tested everything and sent back a new motherboard and memory. When I put everything bak together again there was still no signal output! Again I check with my GFX card and again there was no video signal output! I thought it might be the PSU not being powerfull enough (400w for a high end motherboard and AMD X4 Phenom) so I tried out my 650w and still no signal! I am so lost, help! Thanks.
Try using the motherboards Vga or DVI inputs.. similar thing happened to me.. unforutnately, my GFX was dead (R.I.P. 4870) Im thinking your PCI-e slot may be dead (alson happened to me) if thats the case all you need is a new motherboard.
"sent back a new motherboard and memory" - it's conceivable with a bad brand, but unlikely, to have a double motherboard failure with the same symptom. I assume everything was wired up correctly when you reassembled the system? The only thing I can think of after this is that the CPU was damaged by the failed motherboard.
Thanks all, I think too save myself time I'm just going to tell him to send everything back to the vendor to test again. Your probably right it's a double fault. Thanks anyway.