pc randomly turns on

jabran200 · 27 Nov 2008 at 09:19

O.k so i had a problem before and was told check the switch which i changed to an external one.

the random on/off would become more frequent and occaionally a black screen while in windows.

it would turn on off whilst in bios as well.

I have thuse far changed the motherboard as it had a fault but unrelated to the issue. I also changed ths psu under a technicians reccommendation but woke up to find it on again.

now my dilemma is the major components have been changed so what else can it be? the tech is now saying the pcu can provide a wake up call to the pc? could this be likely?

Admiral Huddy · 27 Nov 2008 at 09:54

Check the Power management options in the BIOS so that the APM mode is ready rather than standby or suspend mode.

Then make sure that both suspension and hinbernation modes are turned off in the Power Option in Windows.

If you still get the same problems than it's most likely to be a hardware problem, Overheating possibly?

Yiou can use the powercfg -a to determine what modes are supported by your system. Make sure these mathc the BIOS settings.

wonko · 27 Nov 2008 at 12:45

Odd. Have the 'random off' problems stopped since swapping the PSU?

A few thoughts about possible 'random on' causes:
- bios set to power on at specified time
- bios set to power on following a power interruption
- bios set to wake on keyboard or mouse event
- set to wake on lan and some appropriate network traffic
- scheduled tasks set to wake the pc (like virus scanner)

Some of these may be related to standby mode - does standby work reliably and do you use it, or do you shut the PC down completely when this has happened?

Maybe a long shot, but could an errant keyboard or USB device or card trigger a shutdown and/or wake-up? I've come across some odd behaviour from USB hubs before, and if you've already swapped the PSU and MB I'm struggling to think what else it could be. If this happens regularly enough to tell, you could try disconnecting / removing things one at a time to see if it makes a difference.

agent_paul · 27 Nov 2008 at 13:17

wake on lan might be something to check too if the machine just switches on itself. i knew someone's friend that had a machine that switched on everytime the telephone rang

jabran200 · 27 Nov 2008 at 16:32

thanks gonna check once i get home.

I had though the psu might have sorted it out but i woke up this morning with the pc quitly humming away.

gonna scrutinise the bios settings some more and disconnect the usb micrsoft wireless mouse and keyboard and see if it happens. It hasn't turned it self off yet but the only symptom that has returned is the automatic turn on.

jabran200 · 21 Dec 2008 at 21:50

Just a quick update

u had checked everything on the pc and finally came down to the cpu. I switched it from my other am2 computer and it seems fine soo far (2hr20mins) but it does last a long time if its been off for a while so gonna wait until tomorrow morning. if th pc isn't on in the morning it will confirm it.

Thanks