Daniel- yes, all six GPU work fine independently but windows 10 does not see them all when plugged in together. It will only see up to 5. GPU seems okay, its a brand new 1200 w platinum evga. I also tried completely wiping the GPu drivers with DDU and still no joy.
Im starting to think this may be a windows 10 problem. I may reinstall.
Thanks for all the suggestions, please keep them coming!
Do you have extra riser?
Did u try another power cable to riser and gpu?
It might sounds stupid, but changing power cables work for me sometimes, and did you use metal or aluminum frame? sometimes the solder on the riser poke out of the form and short.