Hey, I just bought a new EVGA 1200W power supply and can't get it working with the motherboard. I took the motherboard out of the case- nothing plugged into it. If I plug in just the motherboard cable (24 pin), the case fans run and the motherboard. If I plug in the CPU cable to the motherboard, nothing will start (hear a faint click in the PSU when I hit the start button). I tried with another motherboard (ASUS Z390 Maximus XI), same issue. 
 
I tried the 24 pin test device that came with the PSU. I can hear the PSU fan come on. If I plug in the CPU cable (not plugged into the motherboard, just plugged into the PSU with nothing on the other end) it doesn't run (hear a faint click in the PSU, no fan). 
 
Should the PSU fan still come on if a cable is plugged into the PSU's CPU slot but not connected when using the test device?
Is there something else I can test, something I might be doing wrong?

Welcome to the EVGA Forums
 
The 24-pin & CPU power -->  Must be connected to MB for the PSU & PC to start ... your MB have buttons on it --> start & reset ?
 
Only use the cables that came with your PSU
 
Confirm that the correct end is connected to the PSU & device
 
Confirm that the little latch is in the locked position
 
Could be a tight fit & cable is Not fully inserted somewhere ... or one of the pins got pushed back inside of the plastic end
 
 
Ultimate Self-Starter Thread For New Members
 
 

Sounds like the cpu cable is causing a short.

I replaced the CPU cable and it worked. Thanks for the sanity check all.

staticvars
I replaced the CPU cable and it worked. Thanks for the sanity check all.

Great
 
Have to wonder if someone put the wrong pin in the wrong slot