Believe it or not I'm running one full rig with a seasonic 550 watt 80 plus gold psu
I suspect this is the cause of all your problems right here
That's BARELY enough to power a full rig.I <3 anything Corsair in the 850W range for these guys.
I don't think that's true though. According to my power meter a full rig with v2.3 h-cards (the pci ones) is consuming 450 watts at 520 gh. 450 watts is at the wall of course.
But I still think that it would likely be better to give the power supply more room to breathe. Voltage ripple on the 12V rail is likely to occur more frequently at higher loads and the h-cards may not like this.
I think another solution would be to trim down the full rig by 4 h-cards. I was told by punin (from Bitfury Strikes Back -bfsb) that 12 h-cards is a more stable config.
Keep in mind that you are asking these PSUs to push all that power over the 12V PCI-Express power leads. They were NOT designed to do this. They were instead designed to push about 50% of their power over the main ATX connector to a motherboard. That is why you need PSUs that are spec'd far above what the actual power draw is on a full rig -- the 12V rails for the PCI-Express power leads were never designed with that in mind.
Several PSUs- like the EVGA 1300g2, can run almost their entire Amperage over PCIe. I think the evga can do almost 110A @ 12v, or 99.7% of its rated 1300w
It would suck mighty hard if I had to buy a uber expensive evga 1300g2 PSU to power a 460 to 480 watt full rig. I think we are better off just splitting the rigs.
? 
One of these days I'll learn. 
perhaps with time and tuning the bad cjips will come back on. I had a 'dead' chip on my september starter kit that suddenly began working after a few days of runiing at a higher voltage.
