Please help, very strange computer problem!

[DalyTek]

I just a call from my brother asking for help with his PC. I haven't gone over and looked at it yet, but his description is very puzzling. Here is what he told me:

Last night, while he was at work, his wife watching TV and the computer turned itself on. For some reason, she was unable to turn it off my normal means, so she flipped the switch on the back of the power supply to turn it off.

Now this morning, they flipped the switch back to the on position, and they hear the fan spinning and the power LED on the front of the case comes on, but nothing else. No beeps, no signal to the monitor, nothing.

My first guess is a short in the ATX power switch. I built the computer for them about a year ago, it's a Duron 800 CPU on a DFI AK74-EC motherboard. Power supply I believe is a 300-watt ATX. Just can't seem to figure out what would have caused it to do this, wanted to get some ideas from here before I head over to take a look at it.

Any ideas??

 

[Spuffin]

you just state that they flip the switch on the back of the power supply. Is it possible that they flipped THAT switch and ONLY that switch. Read: turned on the power supply but didnt push the power button on the case to feed power to the board.
it's just a thought. As for why it came on it could have some Wake On Lan or Ring feature enabled in the bios

 

[DalyTek]

No, he said that pushing the power button on the front of the case does nothing. It sounds like it is on (PS fan spins, power LED on) but nothing more. I know my machine, if I flip the switch on the power supply on, the fan will spin and the LED will light for a second, then shut off. Then I need to push the power button on the front to start up. What my brother is having and that the fan spins, LED lights up and it stays that way. Definitely something wrong, I'd guess.

As for the wake-on-ring, that's a possibility, but they have been running this computer for a year, I would think they would have received a phone call while the computer was off at least once before this. No lan card in the machine, so souldn't be a wake-on-lan issue.

 

[GAZZA]

Mot sure if this will have any relevance for you .

My friend recently had a problem kinda similar where the pc would boot up on it's own for no reason whatsoever , it turned out to be the ACPI management .

I can't remember now if he changed his pc over to standard or disabled ACPI in the bios .

 

[copyfixer]

My .02

I am not sure why it would turn on by itself, you are possibly right in your theory. I have a duron 700. Initially I RMA'd the bareboned system back because of what appeared to be the power supply. Same scene as your case. Fan was spinning, power led on etc. It turned out to be the ram chip I was using. I might suggest that you remove everything but the essentials to the mb and go from there. Good luck, post back on what you find.

 

[DalyTek]

I went and picked up his computer and did some troubleshooting. Turns out the power supply was on it's last leg (it's dead now) and it took the motherboard out with it. I plugged his CPU, RAM and power supply into my ECS K7S5A motherboard and nothing, power supply wouldn't turn on. Hooked up my power supply to this setup and it booted right up. Everything back into his board, with my power supply, no boot. Looks like I'm going to have to get him a new motherboard and power supply. Not going to make for a very happy brother....

 

[copyfixer]

Good job troubleshooting

 

[poppasp1ce]

Looks like I'm going to have to get him a new motherboard and power supply. Not going to make for a very happy brother....

you never know, if i were getting a new motherboard and psu, i'd be happy.