Is it possible that my motherboard died?

[BoboTheSpartan]

A couple of days ago I was on my PC, playing The Sims 3, and all of a sudden my PC turned off. At first I thought that the power went off, but I checked my monitor and it was still working. I tried turning on my PC, but nothing was happening, no matter how many times I would've pressed the start button. After hours of reading online for a solution, I bought another power supply. I figured out that the old one got toasted (it had a power of 480W). One day before all of this happened, I changed my video card from ATI Radeon HD 4550 to GeForce GTS 250. The new power supply has a power of 580W, and after installing it, all my fans started working, and I thought that I fixed the problem, but after I connected the computer to my screen, nothing would show up. I tested out the new power supply on a older PC, and everything was all right. I tested the Memory RAMs using a friend's computer, and they were ok too, as is the video card. I tried unplugging and plugging back all the cables from my motherboard, but still nothing.

Here are my current PC specs:
Motherboard : Gigabyte GA-P43T-ES3G
Processor : Intel Pentium D 935 3.20 GHz
Video Card: Gainward GeForce GTS 250 512MB DDR3 256-bit
Power Supply: Hiper Type-R 580W Modular Power Supply
Memory RAM : Kingston HyperX Blu 2GB DDR3 1333MHz Dual Channel Kit
Hard Disk : Hard disk Seagate 500GB SATA-II 7200 rpm 16MB Barracuda 7200

 

[ur6beersaway]

The day before were you running the NVidia drivers? Pull the card and plug the monitor into the mobo?

 

[BoboTheSpartan]

The day before were you running the NVidia drivers? Pull the card and plug the monitor into the mobo?

To be honest I did install the NVidia drivers, but I don't think that the Video Card is the problem. I tried putting back the ATI Radeon HD 4550, and I still have the same problem. If it has anything to do with the video card, it might be the PCI Express slot, and I don't have a video card incorporated into my motherboard, therefore I can't test it out.

 

[BoboTheSpartan]

I solved the problem. It was the power supply. I don't know exactly why the new one didn't work, but I borrowed another power supply from a friend, and that one worked. I also tested the Hiper Type-R 580W Modular Power Supply on that friend's computer, and it didn't work there either.