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Last night my computer seemingly broke down completely. I wasnt looking at it when it happened, but I could hear the entire thing shut down. It was only idling in desktop at the time... Afterwards I could not power it back on.

The LED on the motherboard is glowing green, so there must be some power running through it, right? I've tried detaching all the PCI-cards and still there is nothing. It just doesnt start. There is no sound signals from the motherboard or anything. All I can hear is a faint electric "click" when I push in the power-on button.

Im suspecting the CPU is wrecked, but how can I be sure whats causing this?

OS: Windows 7 Ultimate
CPU: Intel Core 2 Duo 3.0Ghz
Motherboard: Asus P5E X38
GPU: Asus GeForce 8800GT

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Have you tried removing the power plug for 10 seconds, plugging it back in and then trying to switch it back on again? Sometimes, the PSU needs to completely lose power in order to reset itself.

Failing that, I had this exact problem. I had a green motherboard LED but it would not switch on. It turned out to be a faulty PSU.

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Yeah, I tried that to. Perhaps I shall try to power it up with a new PSU.. thanks :) – o01 Feb 13 '10 at 19:25
Okay, just tried to power up the computer with a different PSU I know works on another computer. Same result, a short electric "click" followed by nothing... – o01 Feb 13 '10 at 19:49
Hmm tricky one then. That only really leaves the motherboard and the CPU. I've seen my fair share of failed motherboards, but CPUs...? I dunno. Haven't got a spare motherboard you can test with have you? :-) – Kez Feb 13 '10 at 19:56
I'm afraid not.. – o01 Feb 13 '10 at 20:03
have you tried clearing the board of all charge? Remove the power supply and hold down the power button you should see some lights light up then dim/turn off. continue to hold it down for about another 30seconds. Then add the power supply back. This just removes any charge on the board (except the bios battery THIS DOES NOT RESET THE BIOS). Also remove anything that isn't essential so disk drives etc, disconnect them all. just limits the things that could go wrong. – David Golding Jul 16 '15 at 10:36

My first thought was that the power supply had blown one of the 12V rails. A friend of mine had the same problem. No boot, but the light on the mobo was on.

Since you've eliminated the power supply, can you try re-seating the ram, cpu etc.

If that doesn't work, and you have another machine to act as a doner, you cold try swapping out parts one by one.

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Given the troubleshooting you've already done, it sounds like your motherboard may be fried. You can try starting the computer with the CPU taken out of its socket to eliminate that: the motherboard should start up without a CPU enough to warn you that it's missing.

It may be as simple as some failed capacitors, though. If you or a friend are comfortable with soldering, you may be able to identify any blown caps and replace them.

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