I will receieve new PSUs today.I will report the results.
I am running one S5 with CX750 Corsair.If it is a borderline PSU we are in trouble we have more than a hundred with this configuration.
I worry for you check this review out.
http://www.hardocp.com/article/2015/01/21/corsair_cx750_750w_power_supply_review/4#.VbkQBXiov8syou are somewhere in between test 3 and test 4
the psu flatout crashes on test 4. which is 60 amps at 12 volts or 720 dc and of course you should be using
1150 x .52 = 598 dc at stock settings while 600 out of 720 sounds good. if you run 24/7/365 you need to derate by 20% so 720 x .8 = 576 dc
and stock setting is going to use 598 dc.
So you are running them beyond safe derating. and we do not know what safe is since 720 failed so 720 x .8 = 576 is not really safe.
and you have 100 of them. I really suggest dropping your freq setting under stock 350 it simply is not safe.
But I am not an electrical guy. just a miner.
if I had to run those psu's with s-5's I would start at freq 275 and maybe raise a bit to 287.5 or 300