After working through suggestions from post in Jan 2014, I still have the same errors. So far, I have replaced both CPU's, Motherboard, new copper heatsink and new Daughter card. I have (9) sticks of 8gb PC3 - 10600R 2Rx4 Samsung memory in it. When powering up, I get immediate 2, 3, 4 green flashing and solid amber power button. According to the service manual, this indicates "USB subsystem configuration activity in progress or USB subsystem failure". I replaced Motherboard and new board acts exactly like the old board. Any ideas would be greatly appreciated as this PC is wearing me out.
Thanks,