PC problems all up ins

Bergy

I plugged a usb cord into the front of my pc.

The cabled (connected to an old camera) locked up the pc.

The keyboard failed to respond so I manually powered down.

A little while later I went to turn the PC on again and the fans started but shut off after a few seconds and the power light on the front flashed.

I had to unplug the computer completely to get the light for the power supply to come back on once it was plugged back in.

I pressed the power button again and received the same results.

I opened up the computer and tested the power switch by shorting out the pins on the mother board for it and the switch does work.

The fans run for about a second but no drives boot or even attempt to.

The light on the wireless card comes on for a second as well the shuts off.

I'm not sure if its some sort of power supply failure or a motherboard failure.

Ravenger

I'm not expert, but did you unplug your USB before you tried restarting it? Sometimes Windows will try and boot up off of a USB drive, leaving you at a black screen, but I've never had it shut off on me =\

Bergy

The USB ports work, they still can charge my camera and everything but the computer will not boot past the fans flickering.

Ravenger

what i meant was arethey plugged into your computer as you are trying to boot it up.

Uncle Long

This is important.

However, if the system wasn't even attempting to boot or restart on its own then I would say you've got some motherboard issues.

Though I think it is a bit odd that you're not hearing any spinning HDs.

Bergy

The USB doesn't affect the booting one way or the other.

The first time I tried it after the shut down the usb cord was unplugged.

Its some sort of hardware failure, but is so difficult to pinpoint.

Uncle Long

Alright then. This is what you do. Check to make sure that everything is well seated and everything is plugged into where it needs to go. If you have to, unplug and receipt power plugs, IDE/SATA cables and all of that. Once you've got everything good and snug give it another go. If that doesn't help then check your RAM.

If it's not giving you any beeps at start up then I'm guessing it's going to be a mobo issue because POST isn't even starting up.

stigweard

It sounds like the power supply is toast. You can get a cheap tester for 10$ or so that you can plug onto the end and it will light up if all the voltages are within tolerance, or you can use a multi meter if you know how. Too much power draw on a usb port can fry the motherboard too, though it is pretty rare. In the meantime, you can try a minimal boot - pull everything but one stick of ram, or all the ram if you have a speaker attached to the motherboard. You should ge t a beep. Before you do that, you should unhook the power for a few minutes, and then reset the bios to default using the dip switch, or by pulling the battery for a few minutes. If you don't get a beep about missing memory, the problem is narrowed down to the board, the psu, or the cpu. From there, you pretty much need spare parts to narrow it further.

Bergy

I've pulled everything and tried the ram test as you described.

It doesn't beep.

I've tested the power plug to the motherboard, there is 4.4 volts running out of all sockets on the plug.

I held the volt meter to the fan as i started the computer up and the fan's voltage shot up to 12 volts (as needed) then it fell back to millivolts after a second and the light on the power supply went off.

I don't understand the problem at all.

I am assuming the motherboard is fried somewhere, but there are no visible black spots on the board anywhere. I can't see the back of the board though. The problem may lie on the underside of the board.

Ruckus

Any popped or domed capacitors, especially around the CPU?

Other than that I'd say try switching your PSU for a known good one.

Bergy

All the capacitors were fine, I checked all of them every where. There wasn't any bloatage on any of them.

I have an old power supply from another computer, but its max output is on 90 watts, and the power supply for this is a 250 watt supply.

Will it run the computer?

Uncle Long

Probably not. See if you can't find another power supply to try.

And, stupid solution that sometimes works: sometimes shit can get behind a motherboard, like a loose screw or something, and mess with it.

But, honestly, this sounds like either a power supply issue or a motherboard issue. Try switching out a power supply if you can find one or order a new one and OEM if that doesn't work.

Actually, see if your power supply has any kind warranty...

Bergy

The computer is well past warranty.

I guess I will have to order in a power supply.