I've had this problem before, it fixed itself for a while, but now it's back with a vengeance.

Currently running 10x580s and 2x560s, W10 Pro, 2x1000W PSUs, latest amd drivers, sgminer or claymore depending on the algorithm. On ethash, using around 600W on 1 PSU, 510W on second, measured at the wall.

Mining runs fine for a varied amount of time, anything from 1hr to 2 days. Then randomly, it's as if the 2nd PSU just shuts off. The fans etc stop, and wattage measures 0. I've tried checking risers, cables etc and I can't seem to identify the problem. The only thing I can think of it being is some sort of surge or overload at the wall or powerbar, but I'm using a 20A 2000W surge protector.

Any ideas at all, either on how to narrow down causes or find a solution? Happening very frequently now.
 
Thanks all