Attaching power cord starts power without switch?

[kattmarl]

Emachine with XP Home - was running fine, but in the middle of copying a file got an error "Windows has encountered an error and will shut down."

The machine then refused to boot.

When I plug in the power cable, the PS boots without use of the power switch. No POST, no display, no error beeps. Power seems to be getting to the mobo and hard drive (LED activity), but nothing more.

What on earth could cause this? Where should I start troubleshooting?

Any help would be handsomely rewarded! :giddy:

 

[DragonFury]

u unplugged the power and still nothing ? u could try clearing the cmos , if u cannot locate the jumper unplug the Power cord , open the side case up and then locate a watch battery remove it count to 30 and then replace the battery and then rehook power and see if it works that way .

 

[kattmarl]

Yes, I removed the battery... waited, replaced it.. rebooted (ie. inserted the power cord again) with the same results. Can't seem to figure out why there's not error beeps or anything. And no display? Odd... Any other ideas?

 

[Vigilante]

This is a common problem among OEM PCs (booting as soon as power is plugged in). And often becomes a CPU or motherboard issue.

Taking the battery out for 30 seconds may not clear it, as the charges in the PS could run for minutes before going dead. One way would be to unplug it, with battery out, and then actually press the power button, this will force the mobo to suck up any leftover charges from the PS. So leave it unplugged, press the power button a few times, and for at least a few minutes.

Otherwise, something more serious could have happened. Overheat? CPU died? CMOS crapped out?
You would have to start swapping parts.

 

[alphnumeric]

There is a setting in the BIOS that controls that. It's called "state after a power failure". If it's set to "on" the PC will power up as soon as you plug the power cord in. You want to change it to "off". It could also be that your case power on button has shorted out. Un-plugging the cable for it from the mother board header will solve confirm that.