Computer won't turn on

[2Btoo]

Chaps,

When we woke up this morning I discovered that the RCD for the upstairs sockets had tripped overnight. Resetting it was easy but the desktop computer wouldn't turn on once power was restored. The machine is always on (last rebooted a month or so ago for a kernel update). It's therefore worth bearing in mind that the RCD trip was caused by the computer.

The power lead is known good. Pushing the power button sometimes produces a flicker of the power light but nothing more. Removing the CMOS battery hasn't made any difference but I'll try putting a new one in.

Where do I start with finding the problem? If it's easier to post a link to a good online guide then please do so.

Thanks for any help you can offer!

[SantaBarbara]

Try another socket and different power lead

[parabolica]

Last time my old tower PCR refused to start it was because of a dead fan on the CPU cooler; it was plugged directly to the motherboard and apparently the MB required to have a signal from it before it would boot; it was a powercut that started my problems and I reckon it fried the fan as it was completely dead.

[sunbeam alpine]

Possibly a blown power supply unit. Don't be fooled by the fact that the lights flicker - the PSU puts out 12v & 5v so it might only be partly fried. Worth trying another if you've got an old pc lying around.

[Sheepshanks]

parabolica said:

it was a powercut that started my problems

Yes - obviously you need to start with the computer but worth bearing in mind that it's possible the fault could be somewhere else and the power going off buggered up the computer. I stopped turning IT stuff off when I go away after a printer and then a router wouldn't restart.

[2Btoo]

Chaps,

Thanks for the answers. Santabarbara, it's a known good socket and lead.

I share the sentiment that it could well be the PSU that's gone pop but, short of swapping in another one (which I don't have), what's a good way to diagnose it? Or do I just stump up for another one and keep the new one for future use should it turn out that the old one hasn't failed?

[2Btoo]

UPDATE: 'Twas the motherboard battery! New battery and it seems to boot.

Sadly it seems that it has lost all the BIOS settings and I can't remember what they were, which is a prize pain in the butt. Still, it should be recoverable from here.

Thanks for your help.