I disconnected each hash board's data cables and power running to each one, end result was no hashing.
Zeus had recommended trying to swap out all of the data cables and that also had the same result.
All I have is a volt meter to check things, those power supply instructions seem to require a few more tools.
How about the logs? Have you checked the logs?
While testing them one by one, you need to record and save the kernel logs, and compare them. Let's see if we can notice some changes on the logs, like different errors, but if the logs still show the same error, then you don't have a choice but to test it with a known working PSU and control board.
However, as you said before, you just updated it to the latest firmware, so it's impossible that flashing the unit ends up killing the PSU or any hardware from the unit. It was supposed to be only a program issue because that is the last part of what you do before it mess up.
Maybe the 4-pin wire is broken; like we said before, the control board should give a signal to the PSU before the PSU opens the power for the hashboards.
Check that wire if there's a resistance using a multimeter. If all the wires on the 4-pin cable have resistance, then you don't have a choice but to test it with working PSU.
