Good afternoon,
We just received our EVGA BQ 850 Bronze power supply and did the optional power test with the PSU testing tool.  Fan started to spin as soon as I turned the rocker switch.  When I plug the power-supply into my motherboard, the fan does start.  I have tried to power it on with just the motherboard, with the other 5 peripherals plugged in and with everything plugged in and the case closed.  No power is being delivered.  What's my rookie mistake?  Or is the motherboard suspect?  Thanks in advance for your assistance and please let me know if any further details may be needed.  -Charles

Sajin
Hard to say what it is without having spare parts to test with. Got another known good psu to test with? Checking all the voltages with a multimeter is another option to see if all the voltage rails are within spec.

Thank you for the suggestion. I’ll check the rails to make sure their volts read correctly.

All the pins measure correctly on the 24 pin connector. As I had it running I was turning it off and plugging in the various components to see if I could get anything spinning. The only one that powered on was the GPU. Those fans were spinning as well as the PSU fan. As soon as tried a ssd power connection, no fans. And then I have to take it back to just using the PSU testing tool without any other components to get any fans spinning again. I’ll check the PSU that I replaced to see how it measures up on the voltmeter.