Welp, I crashed and burned. Hard.
I made a set of cables and installed the GPU. Will not start.
Took it back apart and discovered I’d made an error. The DELL plug has 2 major differences from the EPS-12v plug, First, the jumper for the sense pin (I did that correctly), and then for some reason Dell decided to completely swap position on all the pos and ground wires (this is where I FUBARed). I made mine like the EPS12v, not the DELL pattern.
That’s a dead short.
I dissasembled my cables and rewired correctly.
Server will not start.
I removed the cables and GPU.
Server will not start.
I unplugged the server, pulled the Power supplies, yanked the CMOS battery, and held the power button for 30 seconds, then reinstalled everything with the original (750w) power supplies.
Server will not start.
When first plugged in, the blue led near the power button comes on, the power supplies illuminate, and I can briefly hear a light fan noise. Pushing the button extinguishes the blue light, and then 5-10 seconds later, I get 2 error messages on the LCD screen VLT0204, which is a main board voltage error.
Besides replacing the motherboard, anything else I should try?