Computer shuts down (turns off) unexpectedly

[AMD-homebuilt]

Hello All:
My new Windows 2000 box (Athlon 64 3200, DFI Nforce socket 754)
always powers off unexpectedly - last time(most recently) was when I changed video resolution -
AIDA32 reports voltage may be at fault :
+12V = 11.07V
-12V = -5.4V ??????

-5v = -3.92v ???????

PS is new, Cooler Master 500W, bought from NewEgg

Any Thoughts ???

THANKS

-Michael

[mobo57]

What else do you have in the rig, such as vid cards? Could be you are underpowered. I really don't trust those one size to fit all reporting programs too much. AIDA reports my main system as being a Unknown CPU in one place, and correctly as a Core 2 in another. It also reports that it is running at 3780 mhz (16x236), where I am actually running at 3420, (380x9). And it does not give my voltages at all. What does the BIOS show?
Also, have you checked your temps? Could be temp related.

[Ol'Tunzafun]

Is that CoolerMaster the "Extreme" or the "Green" model?
I'm just wondering because the "Green" model doesn't even have a -5v rail.
A $15 multimeter or a $15 PSU tester will give you a better idea about the voltages.
Like mobo57 says, it could be heat related or it could also be a faulty dimm. Try running memtest on it.
http://www.memtest86.com/
That said, the PSU is the usual suspect.

[BipolarBill]

Does the BIOS beep at all when it shuts down?