Not sure about your problem, but it does sound similar to mine a year ago. One day the power button did nothing. Actually, I think the fan on the motherboard would spin slightly, but that was it...

A $35 dollar power supply fixed it and I'm using it right now.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85