We need a comprehensive report of the states in which people's boards are going bad. There are a ton of reports of bad boards, but little useable information.
I think that it would be helpful to Barntech's team if we could list how boards were hooked up, i.e. miniplane or not, pci-e power or not, etc. I would also think that powersupply type, with as many details as possible would be helpful. Reports of failed boards don't tell anyone much, other than failure rates.
550 watt psu,no backplane used,used 2-4pin molex lines-2 per line(each molex cable had 3 connectors,used 2).
No other devices on PSU except mobo/cpu(45 watt dual core)/hdd/dvd rom & NVidia 8100 non powered vid card(no external connectors).
No OC'in was done,ran @ stock CGminer settings,got CGminer from drillbit forum:
https://github.com/drillbitsystems/cgminer/releases/tag/3.8.1_drillbitNo green light is the problem on 2 boards.
I miss anything

Sounds like you may have ran the board at suboptimal power by having the other computer components attached. Those could easily draw enough power to have a problem for the boards. I suggest listening to nexus99 and detaching everything from the PSU and trying again. These boards seem to really like having clean power, based on my testing. I got MUCH better results after buying a new powersupply to replace the aging 400watt PSU I was using. I went from 55gh/s over four boards to 70gh/s.
I'm waiting to hear back from Barntech's team in another thread where I asked for the various points they recommend for testing voltages across the boards. I feel that we may learn quite a bit from collective testing.
Thank you for posting such detailed information about your setup. It is very helpful for those of us trying to get an overall opinion of what is causing board failures.