Hi There every body, mine from 2011 was dead, some weekends, try to rapair for this time, until i decide to put 3 ATX PSU 20amp in 12v Rail each, one for J1 conector, one for J2 conector and one for J3 Conector the c conecctor use 5vsb 3.3 vsb and PSU-ON and Ground, this mac pros drawn to much current thats the only way to do it satable 3 x 20amp atx PSU, the only thing you miss is the sleep fuction, but you get you $2000 machine back to life, people goes crazy buying used motherboard, Used PSU that have the same problem as original... serach for j1, j2, j3, c pinout take 3 cheap atx psu thats it, J3 goes for hd, pci 6 pin , j2 goes for cpus , j1 goes for pcie, C goes standby power and memory.... waste 1 hour and $60 to bring your mac to life again, you can takeit to apple support they dont get with failure and take your money, here in my countre apple service take from me a video card replacement hd 2900, they say they replaced psu to, i spend more than $600 for nothing, google you will see tons of people having the same problem, and buying on ebay a used PSU it wont work they all have se same problem in short time you will get failure again, is a PSU problem....