Help please...possible psu or mobo issue

[dismal]

okay..i understand that specs are sometimes necessary to determine the problem...but i think this may have a very simple solution.

The problem: my PC ran fine, I'm usually hard on the old girl and it isn't uncommon to have high (90%) cpu levels with what i use my machine for. anyhow I left everything powered on , which I usualy do, overnight.

Upon waking up i realized that my computer was no longer on. I attempted to start it...no dice...nothing not a fan moving no hard drive turning...nothing.

So, as I have had a similar problem with a psu before, I'm thinking the cause is a fried power supply. But....

while no fans spin and there is no action anywhere else in the pc, for some reason the led for the network adapter still lights up. I can't find an answer in the forums. My thoughts are that somehow the psu has enough juice to run the led but not start the system or that possibly just having the pc plugged in triggers the battery since the network adapter is onboard, it still registers that the light should be on and what i have on my hands is a case issue.

There are no signs of burns or the usual suspects with the motherboard. I'm really just curious if i can rule out the power supply because of that one led...it really is the only indication that i have that says the power supply might not be my problem.

Any sort of help is appreciated.
dismal

[jlreich]

Welcome to the PC Guide forums dismal.

Yes it very possible that the PSU can have a dribble life to give the LED power. There is a small amount of juice that goes through the system even when the PSU is off. Or it's even possible just the 12v rail burned out, but the other rails are still working giving the LED power.

If you have a spare one or can barrow one, try swapping out the PSU with a known good one. Or pick up a PSU tester at the local computer store for about ten bucks.