Won't Shut Down Manually?

**we87** · 04-25-2010, 11:23 AM

I have a M2-ATX psu to my pc, and the IGN is hooked up to a line in the car that is 12v when the car is on, and 0v when the car is off. It auto starts up and shuts down like it should.

However, if I manually shut down the computer while the car is still on, the computer will shut down and then immediately start back up again? Like it doesn't stay shut down when the car is on. Is this normal or a "feature"? Or is something dead wrong.

**Curiosity** · 04-25-2010, 05:48 PM

That's somewhat normal. Most if not all of the intelligent power supplies don't know if the PC is on or off.

All they do is sequence the startup and shutdown. When IGN goes high, turn power on, pulse power button and ignore any change for several minutes. When IGN goes low, pulse power button, wait several minutes, turn power off.

So when you shut down manually, the PSU just assumes the PC is running. Turn IGN off and it will pulse the power button and wait a few minutes to turn the power off even though it just booted the PC. D'Oh!

**we87** · 04-25-2010, 09:46 PM

No no I understand that part... What I am saying is while I am driving, I can shut the computer down and then it IMMEDIATELY boots back up. Like the M2-ATX does know that the IGN is on and the PC is off, so it turns it back on....

This doesnt sound normal...

**Curiosity** · 04-25-2010, 10:05 PM

No, that doesn't make sense. The ATX connector does have an on sense, but I have no idea if the M2 uses that. It may to keep the PC in sync with the IGN state. That would be smart.

What you could do instead is to use a switch inline with the IGN. So to turn the PC off, turn the switch off. That's kind of what I do with my remote.