My computer all of a sudden shut off. When I turned it back on the monitor went into a power save mode and turned off. My computer wasn't able to boot after that. I took my pc to a repair guy and he said my motherboard was fried. I just installed the gigabyte motherboard as well as new ddr3 ram into my case.When I went to boot it up the exact thing happened again. All fans worked but no booting happened, the power save mode comes on the monitor and it shuts itself down. I have went out and purchased another video card but that didn't do anything. does it sound like my new motherboard is fried as well? Please Help!!! I don't want to spend anymore money on this damn pc.

Sounds like the power supply failed (the fact the fans work doesn't really mean anything). Maybe it was only the PSU or maybe it was the PSU and motherboard as a bad PSU can ruin a motherboard. Take it back to the moron at the shop and have them test the power supply. Your new motherboard may still be good. If not, feel free to bitch at them as they should have known. Edit The above assumes the new motherboard was correctly installed.

I purchased a brand new power supply as well. Put everything in and it did the same power save mode on the screen. Do you think it could be the hard drives? Maybe they have failed as well that is why I don't hear any beeps or noises like the pc is booting up?

It's probably not the hard drives. But you can disconnect them from the motherboard to be sure. You don't need a hard drive to get a display. Try removing the RAM. You should get error beeps, because of the missing RAM. If you do get the beeps, that indicates that your power supply and motherboard are ok, and one of the RAM sticks is defective.