Need Help!

[Whyfly??]

Do you have any sort of 3rd party video adapters (graphics cards) installed? If so, take them out so that the onboard VGA can be the primary. Or plug into the graphics card if you have one.

I am using onboard, I will take one from this computer so I will be out for a while.

It didn't work.
I am pretty sure the motherboard is now shot.

This might help.
The original motherboard that was in there only used a 20 pin connector.
The new motherboard used a 24 pin connector.
No biggie because the PSU had an extension for 24.
We plugged in the 20 pins going from left to right, and the 4 pins would just not go in, it was a very tight squeeze, and we had to remove the thing on the side that clicks.
It was just REALLY hard to go in, and that was the only way it would go in at all.
So we plugged it in with 24 and no power, we tried switching the switches the power, and nothing.
So then we took out those 4 pins (It was REALLY hard to pull it out) and then tried power, and it all worked fine?
But now we don't have anything on the screen, could it be caused by those four pins?

We tried the PSU it originally came with, and still nothing?

 

[Whyfly??]

We tried the PSU it originally came with, and still nothing?