Computer turns on by itself:(

[toastedzergling]

It's a very old comp, celeron 733MHz I think, the problem is as soon as there are AC power, the computer will turn on by itself, and when I shut it down in windows, it will go into a "suspend" mode, fans still running, there is still light from monitor etc.

I tried to disconnect all the power sw/power led/hdd led/reset/speaker jumpers, still, it turns on by AC/power,

Any thoughts on this?

[z0n3]

It must be possessed. Quick throw some holy water on it!

There is a BIO option on some mother boards to run like that. Try unhooking the mother board from the PSU and then plug in the PSU. This won't fix the problem but it will help figure out what device isn't working right.

[YouEatLard]

It must be either the PSU or the motherboard. Do you have either you can swap in for testing? Try disconnecting the PSU from the motherboard and then pluging it into the wall. Does it come on then? If yes then it's the PSU. If no it's probably the motherboard. If the motherboard works fine other then this you may be able to cut the 5VSB line and install a switch (one that locks in position) in it. If it's the PSU you'll have to replace it or just deal with it as I don't recommend opening it unless you know whats going on in there.. If it's the older style you may have to go to a smaller used computer shop to find one.

Hope this helps.

[YouEatLard]

Just saw your latest post. Yes it will.

[Amarkarian]

My computer used to turn off whenever i turned my airconditing off

[winterhavok]

To me it sounds like the motherboard is allowing the current to jumpstart it (keep it going). Have you tried reconnecting the PSU, it could just be a short somewhere (probably the 5v wire).

[wdeep4]

Sounds like the motherboard to me.

[winterhavok]

Or it could be a culmination of both, unless the PSU is a good brand name one, I would always get a new psu when I bought a new mobo/proc, just how I did it.