Computer turning off after starting game

[Guest]

just today my computer has started completely turning off when i start up a game. I've done some troubleshooting myself:
-turned the GPU fan up all the way incase it was overheating and checked the resulting temps. Temps are fine. still shutting off.
-I reinstalled the GPU drivers. Still shutting off.
My thoughts are that its the powersupply or memory.

any thoughts?

Specs:
Nvidia geforce 9800 gt
AMD Athlon 64 4000+ (2.4ghz)
600watt powersupply (cant remember the model)

here's what the powersupply readings in SpeedFan are :
Vcore1: 1.46V
Vcore2: 0.00V
+3.3V: 3.33V
+5V: 5.11V
+12V: 11.97V
-12V: -1.25V
-5V: -8.78V
+5V: 5.11V
Vbat: 3.12V

is it me or does this look wrong?

 

[festerovic]

Well, speed fan has issues, so don't always trust what it tells you. Those voltages look off, they should be fairly close to default. I don't know if coretemp reads the same data or not, you could try that as an alternative.

Whenever anyone asks about random reboots, I always point at RAM first. Get memtest and run a test on each stick (1 installed at a time) and see if there are errors.

Those are places to start, I'm sure someone else might have some other ideas.

 

[AdioKIP]

I had the same problem, ended up being my power supply. See if you can run speedfan while the game is running. My pc was fine but as soon as I started gaming and my video cards would draw more power the 11v rail couldnt handle it in the PSU so it would fluctuate causing the PSU to cut off. This was with a 700watt PSU. Brand of PSU is as important as wattage.