Bossnass

I'm running Media Center Edition on a half decent AMD system.

I've been stringent with firewalls and antivirus programs. I haven't noticed any unusual behavior during daily use. It has been recently scanned for virii and spyware.

Then I shut it down. Fans stop, LEDs go out. And then it restarts. Sometimes 1 second later, sometimes 10 seconds later. Sometimes I'm convinced it is shut down for good, but when I wake up in the morning it has booted up.

I've taken to reaching way back and flipping the PSU toggle to off, just because I don't like it booting up by itself. We have two user profiles, so it hangs at the welcome screen, but that doesn't exclude malicious behavior running somewhere in the background.

I don't believe that any software is partly installed or partly updated that is promoting the reboot.

Why? How do I stop it? It isn't the waste of electricity, and I can't hear the fans from other rooms, but something very much offends my sensibilities about my computer turning itself on. I'm pretty sure it isn't self aware though.

Dilbert1234567

sounds like a short in the power switch, how comfortable are you inside of a computer?

__________________
Donate Blood!

"Love is not finding the perfect person, but learning to see an imperfect person perfectly." -Sam Keen

ratbastid

Also "wake on ping" might be turned on in your BIOS.

Plaid13

i have had this happen before from a virus. it was pretty harmless but really annoying. I just used the standard windows fix/basic maintnance. total format and reinstalled windows. Everything was fine after that. Not sure if you have the same problem or not could be ashort in the switch or weird bios settings or a monkey in the case who knows.

shalafi

My initial guess would be either the "wake on ping / wake on lan" or "monkey in the case" theories.

Dilbert1234567

wake on lan is another possibility, but you need another computer sending the magic packet to that’s system's MAC address, and that’s doubtful. And WOL is usually disabled by default in bios. The power switch on all new systems (ATX boards, not AT boards) takes just a quick short to power it on, when I work on mother boards out of the case, I use a screwdriver to turn them on, all it takes is a quick cross of the 2 pins the power button connects to.

If you feel comfortable inside of the case, try disconnecting the power button from the case to the mother board, see if it still powers on randomly, I think the button on the case has an intermittent short.

As for a virus, if the system is shut off, a virus can’t do anything, unless it is rewriting parts of the bios ROM, possible but would have to be mother board specific.

__________________
Donate Blood!

"Love is not finding the perfect person, but learning to see an imperfect person perfectly." -Sam Keen

nukeu666

details?
short between what n what, how to fix it

__________________
Why did the Comp. Engineer get X-mas and Halloween mixed up?
Because Oct(31) == Dec(25)

cyrnel

Very unlikely this has anything to do with software. (Though installing with ACPI disabled can lead to weird behavior with some BIOSs) If it's coming back up after a shutdown it's a hardware problem or most likely an interaction between the PSU and BIOS.

More BIOS settings:
Is it set to reboot on power fail/loss? Disable it.
Is ACPI disabled?

Does anyone in the household own a TrapperKeeper 2000?

__________________
There are a vast number of people who are uninformed and heavily propagandized, but fundamentally decent. The propaganda that inundates them is effective when unchallenged, but much of it goes only skin deep. If they can be brought to raise questions and apply their decent instincts and basic intelligence, many people quickly escape the confines of the doctrinal system and are willing to do something to help others who are really suffering and oppressed." -Manufacturing Consent: Noam Chomsky and the Media, p. 195

Bossnass

Wow, lots of replies. Thanks.

After way too much time searching the bios setup menus, I have determined that wake-on-ping is disabled. It was set to reboot on power failure. I didn't find any ACPI settings, but I wasn't looking very hard for it.

I'm fairly comforatable inside the case, I built this system myself and had to exchange a bad mobo. I could disconnect the switch, but I need to use the computer for most of the afternoon and evening so I don't plan on disconnecting it until later tonight and see if it has powered up in the morning.

Does polarity matter with the power switch? I'm pretty sure that I didn't check when I was plugging the cords onto the posts.


I have an antec sonota II case. Incoming air is filtered and there is a big duct in the way. So I checked for the monkey, but he must be hiding somewhere. I do have far too many binders in the room, it isn't impossible that one of them contained a computer chip that has integrated both itself and the monkey into the computer.

Dilbert1234567

usually its the switch it self, the switch works by connecting a circuit on the mother board, if the switch is defective, the expansion and contraction due to heat can cause it to fire, as well as small pets or any number of other causes.

ACPI is the technical term for power options; most BIOS label it as power management or something similar.

If you know exactly which 2 pins the power switch connects to on sight, you can use any conductive material (screw driver) to momentarily bridge the 2 pins, and this will be as if you pressed the power button. I do it all the time, but I have plenty of practice, if you slip you could do some damage.


Polarity does not matter on the switch, all it does is cross the 2 pins. But make sure that the 2 are connected to the switch, I’ve seen systems that were offset by 1, which caused all kinds of hell, basically one pin from the switch was plugged in to the switch and one into the HD activity LED and it got worse from there. as for the reboot on power failure, some times this gets screwed up and it thinks it was last on and it will boot it self up. Try disabling it. the settings is something you don’t want on anyways for the most part, if you are loosing power, you will probably lose power again soon and you don’t want to lose power when the system is booting (I lost a system to this once, power flickered off, system turned back on, flickered again while it was booting up, OS was toast.)

__________________
Donate Blood!

"Love is not finding the perfect person, but learning to see an imperfect person perfectly." -Sam Keen

cyrnel

And you disabled it? Does it still power up by itself?

You should also check the manufacturer's site for BIOS updates. I've seen some fairly persistent auto-boot bugs that could only be corrected by updates.

__________________
There are a vast number of people who are uninformed and heavily propagandized, but fundamentally decent. The propaganda that inundates them is effective when unchallenged, but much of it goes only skin deep. If they can be brought to raise questions and apply their decent instincts and basic intelligence, many people quickly escape the confines of the doctrinal system and are willing to do something to help others who are really suffering and oppressed." -Manufacturing Consent: Noam Chomsky and the Media, p. 195

MikeSty

Make sure there is no ethernet booting options. I repaired a computer that had that stock enabled (god only knows) and that was a mess.

Cyrnel's diagnosis is the same as mine

Bossnass

I haven't disconnected the power switch yet, I was hoping the bios tweaking would fix it, and although I only changed the 'reboot on power failure' setting. and when it didn't get turned on yesterday and didn't self boot for most of today, I thought the problem somehow fixed.

When it wouldn't turn on at all, I realized I was an idiot and the psu toggle was off, so it wouldn't have booted anyway. I'll try the disconnect the power switch technique tonight.

Most recent version of the bios has been installed since before this problem arose.