I have 2 750W EVGA G2 PSUs. They work individually just fine. I have an ATX connector with ground. I plug the main PSU into the main PSU connector which is plugged into the MOBO and then the 2nd PSU into the 2-wire connector for ground. However, when I turn on the PSU's the 2nd starts spinning immeditalty even before I'vev turned on the first. If I then turn on the first the MBO gives an 99 error on the LCD.
I've tried two ATX connectors from different places. What am I missing?
The mobo is set to turn on with power detection. But I assume everyone else's are configured this way too?
Jump start the second PSU which is powering the GPUs first and then start the first PSU to power on the MOB. Try changing the cables and see if it works. If it's not working no matter what you try, I will recommend you to invest in add2psu, it will save you a lot of time and headache.
I actually have an add2PSU, but no free molex to use it. So have to buy another cable for that.... oy. That little thing was expensive and was happy to use just the ATX connector+ground. Alas...
As for jump starting, isn't the concern that the two psu's should be grounded together?