I installed a replacement Gigabyte GA-X58A-UD5 MB, it ran about two minutes loading Windows 7 Ultimate 64 bit when it shut dow

[Nikki10]

I installed a replacement Gigabyte GA-X58A-UD5 MB, it ran about two minutes loading Windows 7 Ultimate 64 bit when it shut down. It would go on and off every few seconds. This same thing happened to my previous MB after a year of good service. They replaced it with this one. Out of the box, this happened. It is like they sent me back my old board w/o rebuilding it. My old MB was a UD3R. I followed all MFG's suggestions, including using one stick of ram, removing MB from case but keep it connected to see if it was shorting out. It appears that something on the board, heats up and opens and then closes, and keeps repeating this. Does anyone have any suggestions? The MFG is dragging their feet. I tried a few repair shops to see if they can test the board, but they do not have the equipment. HELP:

 

[James Mason]

It's very possible they sent you a defective board, I'd just send it back and ask for another.