System wont post

well i got all the parts in for my new machine in on tuesday. and build it today. and apparently i did something wrong, cause it wont even post

and the weirdest thing is that the system powers up as soon as i plug it in or switch on the main power on the back of the power supply. and then cuts off about 5 seconds later. no signal is ever sent to the monitor. and i get no beeps or alarms.

i thought it may be the connection for the power button (though i might have it in backwards. colored wire=+ white or in the case of speaker connection black=ground) and i defiantly have them in the right spots cause my mobo came with a handy adapter so you cant put them in the wrong spots.

Stumpted

Any Ideas?

Power button is a momentary contact switch - in other words, it doesn't matter which way you plug it on the header, as long as it is on the correct two pins. When you press that button, its the same as touching both pins with eg a screwdriver.

Your PC should do nothing when you plug it in, or turn the psu switch on, until you hit the Power button. Test by REMOVING the power button connector from the mobo header. Then plug in PC, turn on psu. Nothing should happen.

If something happens, you've got a short somewhere, cables not connected properly, the handy adapter is plugged in wrong, etc.

If nothing happens, plug the power button connector back in. If the problem recurs, you have the power button connector on the wrong pins or, more likely, check the power button wires or the button itself for a problem causing a short.

Reminds me of the X-QPACK2 case I had; a factory drone put a screw through the power switch wires, shorting them. It caused the same symptoms.

It wouldn't surprise me if having to not use those wires caused the grounding problem that case also had.