Update - issue persists

So the issue is still not fixed, although I feel like I am getting close.  I would love some advice from this forum.

So I ran 1 GPU on each PSU for 48 hours, no issue.  Then I ran 2 GPU on each PSU for 48 hours, no problem.  Then I plugged in the 5th GPU on the PSU that also powers the motherboard.  I wanted to test the PSU that shoulders a bit more of the load.  I ran this for 48 hours, no issue.

I then plugged in the 6th and final GPU, which is powered by the 2nd PSU.  Crashed after 3 hours.  I changed out my Add2PSU for a different unit and started mining again.  Crashed after a few hours or so.  I changed out the VGA cable from the PSU to this GPU, crashed after while too.

I checked my event viewer and see:  Kernel-Power Event 43 (63).  I googled and a lot of people found this error ties back to the memory or PSU.  I ran a memtest, came back clean.  I have a new PSU on order, a slightly beefier EVGA G3 850 that I got a good price on.  

Anyone ever seen this error?  Am I headed in the right direction with my troubleshooting?

Thank you


*edit*  for the record I have tried 3 different risers as well