Quote from: RickJamesBTC on December 10, 2013, 02:05:28 AM

Turn it off, open it up and check that all cables are completely plugged in. Try swapping ports and cables between pairs of ASICs, see if the problem follows the move or the port. Various methods to determine if the problem is the asic, controller board, or the cable between them.

I will try that soon.

Quote from: davewr2013 on December 10, 2013, 01:58:16 AM

Do you have a flaky power supply?

You really should be able to find a supply that can deliver 12V -- 12.2V -- 11.8V might be an issue.

I believe the PSU is fine, the 2 boards that are working perfectly are both being supplied with 11.8 or 11.9 volts.
I will try using a different power supply to power the non-functional boards.