The mystery of the computer that turns on with the lights....

[blackjackel]

I recently replaced my computer with a new motherboard.

Recently, so I realized that my computer turns on whenever I flick the lights on. By turns on, I mean "comes out of hibernation state", it won't turn on if the computer is 100% off, only if I have it on hibernation or sleep.

Thing is...

It's not connected to the lights, or the light switch, in any way. The only way a relationship exists is that the light socket and the computer are fed from the same electric line, you know, the same circuit breaker. That is, they draw their electricity from the same place.

 

[Automata]

There is usually an option in the BIOS that turns the computer back on if it was already on before the power was lost. This might be triggering.

Alternative option is get a UPS.

 

[ratbuddy]

I'd head for BIOS and disable the various 'wake on' settings until you figure out which one it is

 

[Conumdrum]

I know.

Your lights turning on causes a big drop in AC voltage. Meaning old lines in the house apartment, bad ballast etc. etc. This is sensed by the PC since your PSU drops a bit. The PSU comes up above the min, the 3 or 5 VDC gets better, the PSU sees it as a wakeup.

 

[kayson]

I know.

Your lights turning on causes a big drop in AC voltage. Meaning old lines in the house apartment, bad ballast etc. etc. This is sensed by the PC since your PSU drops a bit. The PSU comes up above the min, the 3 or 5 VDC gets better, the PSU sees it as a wakeup.

I like this. It sounds plausable. That being said, you shouldn't definitely have an electrician come check because that should not happen!

 

[Conumdrum]

I like this. It sounds plausable. That being said, you shouldn't definitely have an electrician come check because that should not happen!

LOL, it's a shot in the dark with a bit my background. Plausable? ummm... Guessimation? Probably.......

 

[blackjackel]

There is usually an option in the BIOS that turns the computer back on if it was already on before the power was lost. This might be triggering.

Alternative option is get a UPS.

You're speaking as if the lights were to power the computer too, they don't at all, they are just fed from the same circuit breaker line. They get their power from the same power line, that's it.

I know.

Your lights turning on causes a big drop in AC voltage. Meaning old lines in the house apartment, bad ballast etc. etc. This is sensed by the PC since your PSU drops a bit. The PSU comes up above the min, the 3 or 5 VDC gets better, the PSU sees it as a wakeup.

This is the best guess that I could come up with too.

Don't get me wrong, I LOVE that my computer does this, i think its AWESOME because my computer is ready for use by the time i hang up my clothes, so I don't want it to change, i just wanted to know WHY.

 

[Automata]

You're speaking as if the lights were to power the computer too, they don't at all, they are just fed from the same circuit breaker line. They get their power from the same power line, that's it.

It depends on the board and how it is programmed. I have a system that has an option, when enabled, acts like this:

If the computer is off when power is lost, do not turn it on when power is restored.
If the computer is on when power is lost, turn on on the computer when power is restored.

Thus, if it was off, it would stay off after a power failure. If it was on, it would start up again. My line of thought is that with the computer in standby/hibernation, it considers the computer "on" and boots the system when the power dips briefly. This is all speculation, though.

What happens if you put it on a different circuit?

 

[Bobnova]

If it's set to wake on keyboard/mouse activity and you have a lot of fluorescent lights and/or high wattage bulbs you might be getting an interesting inductive spike that triggers keyboard/mouse states.

Most likely it's just a drop and rise in the AC input though.

 

[kayson]

If it's set to wake on keyboard/mouse activity and you have a lot of fluorescent lights and/or high wattage bulbs you might be getting an interesting inductive spike that triggers keyboard/mouse states.

Most likely it's just a drop and rise in the AC input though.

That would be one hell of an inductive coupling

 

[wagex]

I know in ky old apartment the wiring was bad enough sometimes when I turned off thekitchen light it would kick off my pc in the living room but they weren't on the same switch either lol something weird with the power spike or something
I know it doesn't help just wanted to share a story bored at work

 

[JonSimonzi]

I have one outlet (we'll call it outlet A), in a completely separate are of my room, that if I just plug something in or out, it will cause my computer, and everything else plugged into the same outlet (called outlet B), to restart. Outlet A and outlet B are on opposite sides of the rooms, and the only ones that effect each other. If I plug my computer into any other outlet, the same phenomenon won't happen if I plug or unplug anything into outlet A. Electricity can do some weird things.