Computor has always ran fine other than a few graphics cards blowing in the past(probably due to high stress in apps and games). The other night though, the screen went all funny in the middle of a game(scrambled, multi color lines). I rebooted, and upon doing so now have the lines at start up as soon as the monitor gets the signal. It still seems to be booting up as normal in the background but I cannot see anything. I have tried swapping the monitor and the graphics card(BFG tech Nvidia 6800 GT) to no avail. Wondering what opinions would be, I think I may be leaning towards a bad agp slot on the mobo(asus p4c800 deluxe), but really am not sure, any help would be much appreciated.

That sounds like a AC power issue. Possibly fluctuating voltage due to something with a high startup current draw in the circuit cycling on.

Bad power supply, poor connections, faulty capacitors. See response 1 and 3 in this: http://www.computing.net/hardware/wwwboard/forum/44984.html

I've now done a visual inspection of the connections and the mobo capacitors. They all seem to be intact and without damage. I will see if I can get a new power supply in there today, and see how that goes. Thanks for the responses. I will update when I've completed that.

PSU is also called SMPS;steady mode power supply; so even if your ac fluctuates a bit your PSU converts it into stable DC with a rectifier, provided the ac is not extremely below the required level. Most probably, your display looks scrambled because of your RAM. And your RAM is sick probably because of a bad PSU.Anyway reseat your RAM and give it a shot. But in any case, buy a gud PSU. Be humble

"PSU is also called SMPS;steady mode power supply" SWITCHING mode power supply "....your PSU converts it into stable DC with a rectifier," The rectifier ouputs will vary with the AC input - the voltage regulators are what provide stable DC voltages. Of about ten PS failures I have seen, none damaged the ram, but it's possible. Of those, two damaged the video card.

Sorry about that; yeah it's Switched mode power supply. Ofcourse o/p varies with i/p,but i didn't wanna complicate things further more by putting in info abt the regulators also.I suppose even the rectifiers might sound odd to people not familiar with these terminologies. So i skipped the regulators. I had an SMPS that damaged a video card, one mouse,a floppy drive and about 3 RAMs but without damaging itself. No more issues after a replacement. Be humble