Powering up.

[ReignInPain]

If you dont like your motherboard to any sort of power switch, will your computer power up just by turning on your PSU?

[jdbnsn]

No, the power switch shorts the green wire with a ground (black wire) on the main power harness attaching to your motherboard. Without the short between these wires your PSU stays "off". I would not advise trying to bypass this by shorting them manually.

[ReignInPain]

Cool, cheers for the info! +rep

[xmastree]

I had a thought about this (and the other similar thread). If a smallish electrolytic capacitor was placed across the 'power on' pins, it might just bring up the computer as the power was turned on. I don't have the means to try it, or I would.
The idea is that when it's off, and the psu is also off, it's all dead.
Turn on the psu and the capacitor will begin to charge. Initially, when it's completely discharged, it will be very low resistance. Hopefully enough to convince the mobo that the power switch is pressed. Once it's charged up it'll appear open circuit, like you let go of the button.

Anybody wanna try that theory?

My gut feeling tells me I would start with about 10µF, too big and it'll be 'holding' the button on too long.

[jdbnsn]

But would that capacitor hold a charge for any length of time after the PSU is powered off? If so this would defeat the safety shut down mechanism if the voltage or temperature rose too high. I guess it would matter as much on a system you don't mind losing, but I would'nt think it would be a good idea on a main build.

[tybrenis]

Just press a screw driver onto the two header pins on your motherboard to short it out. That'll start up your computer. I do it all the time testing PCs without a case.

However, do it at your own risk. I've never had a problem with it but I won't be responsible for explodinated computers.

[GT40_GearHead]

explodinated computers

=]
good one mate

[xmastree]

But would that capacitor hold a charge for any length of time after the PSU is powered off?I think it would discharge back into the motherboard. There would be a minimum downtime, but then you shouldn't turn a psu off and back on immediately anyway.