PC Reboots on it's own

[handscombmp]

Sorry if this is in the wrong section as it could also be software but i have a feeling it's most likely to be hardware.

Last night i rebuilt my pc using the specs shown to the left only keeping the case, HDD, PSU & dvd drive from my old pc.
Reinstalled windows and fine.

So i went to shut the pc down last night which it does but then after about 2 secs it just restarts it self.

Anybody got any ideas.

I can't decide if it something in the bios or if i've somehow managed to rig up the powerbuttons wrong.

[peterb]

Checking the power button is only a few seconds work, but as it is a normally open momentary operation switch, I'd tend to rule that out (unless there is something else connected by mistake to the power connector pins, like an LED).

Check that out, then I'd like at the BIOS settings, particular;ly those associated with power management.

[jim]

The pixies attached your power button to the reset header?

Seriously though, I would check all of them are plugged in properly and firmly, since they *could* be at fault. It's caused me issues before

[handscombmp]

I'm out of idea's.

I've had the taken out the fp headers and been turning on the pc with the button on the mobo but it still reboots.

I've even removed ever usb device but it still does it.

The only thing i may try if updating the bios but i don't want to do that as bios update i know can go wrong but i'll guess i'm going to have to do it.

[Tonka777]

The last time I had a PC that restarted randomly, it turned out to be a dieing PSU. The PC was fine 85% of the time, and could do intensive tasks fine, when it didn't randomly reboot!

[handscombmp]

The last time I had a PC that restarted randomly, it turned out to be a dieing PSU. The PC was fine 85% of the time, and could do intensive tasks fine, when it didn't randomly reboot!

It's not randomly rebooting though.

I switch the pc off and dead on about 6 secs it turns itself on.

[handscombmp]

Well i've just update the bios and it still does it.

I also booted into winki (a linux distro that come with the mobo) and shut it down and it still restarts after shutdown so i think we can say it's not a windows issue.

[jim]

You got any spare parts you can swap in/out?

[handscombmp]

You got any spare parts you can swap in/out?

Like?

When i've just upgraded the pc and the i changed the Mobo, CPU, RAM and the cooler.

Before then everything else was working fine. When i've done a fresh install of windows

[TooNice]

Your PC has a will of it's own
[I assume that you've disabled any settings related to booting up the PC on click/keyboard press in the bios?]

[Repressor]

A very long shot but might the green wire in the 24-pin MB power connector be shorting out on the case? This would cause the PSU to start, and I guess the rest of the computer to start when it does.

[handscombmp]

A very long shot but might the green wire in the 24-pin MB power connector be shorting out on the case? This would cause the PSU to start, and I guess the rest of the computer to start when it does.

But it's been fine before

Your PC has a will of it's own
[I assume that you've disabled any settings related to booting up the PC on click/keyboard press in the bios?]

As far as i know but there are some random things which i'm not sure about

[handscombmp]

From what i've read on the internet it sounds like it could possibley be cmos battery.

This could make sense as the board has been left for a couple of months since it was made not doing anything.

i'll try reseating it tonight and perhaps buying a new one.

Does this sound like it could be a solution or is it just me desperate to solve this

[this_is_gav]

Easy way to check the above... is it keeping the system time correct?

I've had this previously. For me it was a combination of the BIOS being set to turn on a PCI/PCIe device receiving a start up command (used for Wake on Lan).

If this is the issue, then either turning off those settings in the BIOS or changing the driver settings should fix it. For me the setting was for a network chip being set to start up the PC on receiving "magic packet & pattern match" in the drivers (Device Manager > Network adapters > double click on the network adapter > Advanced tab > Wake-up capabilities). I changed it to just "magic packet" as I did want the PC to start up remotely, but the automatically powering back on problem went away. You can also disable the "Wake from shutdown" option, which may overrule the above option.

It could also be set to start the PC if you have a TV tuner and it's possibly waking the PC start a recording soon or download the latest guide (though I've no idea how you'd disable either - I have read about both though. Mine never wakes the PC to download the guide or start a recording).

[jim]

Like?

When i've just upgraded the pc and the i changed the Mobo, CPU, RAM and the cooler.

Before then everything else was working fine. When i've done a fresh install of windows

Well, mobo, CPU, RAM, PSU. PSU would be the obvious one to try an alternative unit.

[handscombmp]

Fixed it. (touch wood)

Turns out all i had to do was take the cmos battery out and reinsert it.

Really weird.