PSU dead?

[97FirebirD]

Hi there, this mourning i went to turn on my comp and it came on but no video signal. I tried rebooting a few times and turning the breaker on the PSU on and off a few times, but still no video and i think no mouse or keybord lights.

But the ower light came on and the fans came on too, i have an extra PSU that i put in and everything started just fine, but the i went to play MOHAA and it loaded fine untill i got into a game and the comp locked up.

I tried this a few times and it locked up eveytime and even in RtCW both are Q3 engine games and both lock up but played fine before this problem.

I can load up to desktop and surf the net fine but evertime i try a 3d app it locks up, so my question would this be a mobo or video card problem?


Heres my specs:

-Duron 1.3
-512mb ram
-40gig WD drive
-Gf4 4600ti 126mb
-SB live value
-ECS K7S5A mobo
-LG combo drive
-old PSU generic 350W/new PSU generic 420W

Thanx for any advice, this is a wierd problem humm.