trouble

I've a second hand MSI Z170 board that is giving me grief with a post code of 71 (late south bridge initialization?) and I can't get it to POST at all. The board is the Z170A XPOWER Titanium with dual BIOS but neither of them seem to work; code is the same. I've cleared the CMOS, tried different...

I have never encountered something like this so I was wondering if you guys also thought the power supply sounded like the culprit. Subject is a Dell OptiPlex 7040 built Q4 2015 - coworker was using it with few troubles up until a few weeks ago when he quit so I traded up from a 3020. I had...