Power Supply problem or something else

[Xerlic]

On Sunday my computer made a bzzt sound and suddenly shut off. I immediately noticed a burnt smell, so figured something was fried. I realize it was the power supply. So I take it out and replace it with an ancient power supply from an old computer. Things work semi-fine. The computer instantly shuts down if I open pretty much any game, so I figure that the graphics card isn't getting enough power so the computer shuts down.

I go out and buy a 500 watt power supply. I figure this is more than enough since the original power supply was 420 watts. Go home, hook it up, things work OK for a few minutes then computer shuts down once I log onto FFXI. I'm kind of annoyed. Restart, log back in, computer shuts down. Repeat this again and I get a blue screen as windows starts that says something about inaccessible boot device. So I boot from Windows CD to run recovery tool and run chkdsk. Computer shuts down.

Friend of mine suggests that when the power supply went, it might have fried some of the RAM. So I pull out all of my RAM except 1 stick, and am able to run chkdsk fine and fix the problem. So windows starts up. So I log into FFXI again. Computer shuts down..

Any ideas? At first I thought the new power supply wasn't able to sufficiently power the graphics card, but the fact that the computer was shutting down in windows recovery tool seems to suggest otherwise, I think. Thanks.

Graphics card is Geforce 6800 GT btw. 350-400 watt power supply is supposed to be sufficient for this card.

[Seditedi]

When your PSU died it could have possibly damaged the videocard as well.
Does it shut down with any game or just FFXI? Also are all the fans working correctly, something could be overheating and causing the computer to turn off completely.

[Don Katsu]

Try a different hard drive.
That's the annoying part of a PSU that goes out, you have to find which random component it took out with it.

[Xerlic]

I doubt it's overheating. All of the fans are working and I've never had a problem with overheating before.

The problem isn't just isolated to games, really. For instance, I had FFXI running and tried to open Firefox and it restarted. It's restarted while playing Starcraft. I lowered the settings on FFXI to make the vid card draw less power, and it still restarts.

Is there any way to check and see if the HDD is the problem? I don't really have a spare one to stick in to see if that fixes it. =x

Thanks.

[Avanarius]

Probably dumb question but do you have the supplementary power plugged in on the graphics card? Or if your board supports it, the additional 4 pin internal molex plug on the mobo too.

If you do chkdsk and it says no errors you can force it to check anyways by typing
"chkdsk /p"

Hell you could always try system restore too. Sometimes it fixes hdd corruption due to power failure.

[Xerlic]

Yeah, I have a power cable running from the PSU to the gfx card lol. I ran chkdsk earlier today and it fixed an error that was causing me to blue screen on startup, but it didn't fix the random shutdowns.

I guess if all else fails I can try a reformat like you suggested. Yay for updating FFXI three times in two months! Thanks for the suggestions.