Please help me fix my computer

[ToyYoda]

OK, here we go. A few days ago my computer crashed as if it overheated. I got artifacts all over the screen and it looked something like this.
ARTIFACTS GALORE!!!

My immediate thought was video card, so I replaced my 9500 soft-modded to 9700 w/ my old geforce 2 gts. Still happened. Its weird though, first it happened once, then again but it came 45 min later. Than faster and faster until every 5 min it did it. I scanned the hard-drive for bad sectors, then I ran memtest86 and it turned out ok. Even though it froze during that once... Nothing feels too hot, I keep my rig cool. Then once when I booted up, the lights came on for a second, then went off, then came on again, then went off untill I unplugged it. I just replaced the PSU w/ an old one that I have and so far its good. I only have the hard drive and the mobo plugged in right now. Before the PSU swap I had everything plugged in.

Here are my specs
Abit IC7 Mobo running 3ghz P4.
9500 soft modded to 9700 (but replaced w/ old geforce 2)
256x2 Geil 3200 RAM
D-Link Wifi card
WD Raptor 36GB 10000rpm HD on SATA. (Windows installed on this)
60GB WD on SATA converter.
16X DVD-ROM
TDK DVD BURNER (THIS WAS THE LAST THING I PUT IN THE COMPUTER, ABOUT 2 MONTHS AGO)

thats about it, NOTHING BESIDES THE 9500 RADEON WAS OVERCLOCKED.

The old PSU was 500W and this one is 350W.

So far everything is running smooth but can a psu cause the screen to look like that?

Anyways, im done messing w/ it tonight. Tell me what you think

 

[NokiaDude]

That PSU is on it's way out. You're lucky it didn't damage anything else. Get a good 550W PSU preferrable an Antec TruePower if you're O/C'ing. Other than that 300-400W is fine.

 

[sandorski]

Try using the 350watt P/S for now, if it works fine the old one is certainly packing it in. The screen shot certainly looked like some kind of interference was happening, it was kinda odd that the 1 ad looked fine though.