New motherboard: still doesn't POST

[Puchu]

A couple weeks ago I put my computer in standby. Came back an hour later to find it dead.

The fans in the psu spin, all case fans spin, cpu fans spin, motherboard light is on. No signal to the monitor.

After a week of troubleshooting I decided to get a new motherboard. It just arrived today.

I hooked it all up: CPU, Memory, hard drives, floppy drive, cd drives and video card.
Turned it on and nothing happened just like before. I removed the cd and floppy drives and tried that.. nothing. Tinkered around with it for a while.. gave up on it twice.

Then... I put a different video card in.. turned it on and it booted into windows without a problem! So just out of curiosity I put the orignal video card back in it. It booted fine then as well. So I hooked the rest of the components up, set it up on my desk, put the side panels back on and plugged it all in. Turned it on and NOTHING.

*sigh*

I removed all uneccesary components again leaving it with just cpu, memory and video card. Nothing worked.

I pulled the motherboard out of the case and assembled it outside of the case. (maybe it was being grounded on the case?) Still doesn't work.

The system doesn't POST at all. No signal to the monitor. My case doesn't have an internal speaker so I can't hear beep codes. (I had it in a different case before that had an internal speaker and I didn't get any beeps then either.. so I'm assuming im not now)

So why did it work those 2 times then quit??? It's a brand new motherboard. The psu doesn't show any signs of having problems.

I don't know what to do. Please help me.

[BinaryMayhem]

I would change the power supply. it may not be putting out the correct voltages.

[Puchu]

I took it up to GeekSquad at Best Buy.

They tested the power supply. It seemed ok.
They tried a different psu and the problems persisted.

Their was 1 thing to take note of though..

With my psu, when you flip the psu on switch all the fans in the case start running without having to hit the front power button.

With their psu, when it's flipped on the fans dont run until I hit the front power button.

Strange?

So I'm starting to think that the problem is more than 1 piece of hardware. I think it may be the combination of the psu and something else.

I'm guessing what I said before indicated that their is a problem with the psu.. even though it's giving the correct voltages... is it not turning itself on and off correctly?

Why does it automatically start running the fans and everything without pusing the front power button when the other psu didn't do that?

This is running me in circles here.

I appreciate it.

[BinaryMayhem]

hmmm, well you dont know if it posted or not because you dont have any signal to the screen. pop the other video card in there and see if it works that way. when you turn on your computer. do you see the floppy light turn on then off?

some things to check:

1:) try another video card.
2:) try another power supply
3:) try another monitor

it is possible the video card died. try that other video card in there and see if it works.

just because the geeksquad tested the power supply doesn't mean its good. some power supplies fail under moderate load. those PSU testers dont do much. the real cheap ones only check to see if there is power coming out of the psu.

when you say no signal. do you not see anything on the screen? or does it say "no signal". what kinda monitor is it? an lcd? it could be possible that it died if you dont see anything on the screen.