I have a dual xeon system with LGA 771 sockets that went dead. I figured, it must be a power supply, so I swapped the ps and I still has no power. I tested both power supplies on another system and it showed the original ps was dead and the replacement was good -- at least the power supply itself energized -- LED on, fan on, cpu heatsink fan on. I ordered another compatible mother board -- an ASUS, vs. the original Super Micro. Same problem with new mother board and 2 new power supplies. When I turn on the ps, the "power led" on the mobo turns on, seemingly indicating power ok to mobo. I connected the power switch, held it dodn, tried reset button, shorted out the switch with a screwdriver, swapped hd's, removed fb dimm. Tried with each of 2 cpu's or both, with fans and without. No matter what I do, the only thing that turns on is the tiny LED on the mobo consistently. Any suggestions? Thanks