My PC won't boot up - please help!!!!

[gmalloch]

The other morning my PC for some reason seemed to switch itself on and performed a series of clicks before it went dead! I tried to turn it on after witnessing this but only the CPU fan started running, nothing else happened with the drives, the monitor or keyboard. I've since tripped it down, rebuilt it and replaced the power unit but nothing different happens. The switch doesnt work either, as soon as I put the power cable in the back, the fan powers up but nothing else at all, no beeps, video signal, lights.....nothing. At my wits end, please help!!

[Thunderchild]

possibly motherboard but a bit difficult to decide without seeing it, is it at or atx power supply atx should not run anything until the power button is pressed

[plowter]

If you've replaced the PSU have you reconnected the on/off switch to the motherboard? The only other suggestion is to change the battery and clear the CMOS. Other than that it sounds like a dead motherboard.

If you've got another PC you could test the individual components (PSU, memory, hard disk). Your data should be safe.

[gmalloch]

Thanks for the answers so far, i'm beginning to think its the motherboard....groan!! The switch is connected up so unless its a faulty switch, its not that. What purpose does the battery serve? I tried the jumpers but to no avail.

[plowter]

In simple terms, the battery provides power to the BIOS chip so that it retains the BIOS data when the machine is switched off. Batteries wear out but usually after years of use.

If you remove the battery, clear BIOS and replace the battery this should reset the BIOS values back to the default settings.

It should be pretty cheap to replace your motherboard.