Yeah there are quite a few people that have issue with flashing, because there are different version for different batch of S7. So people recommend not to flash it. But did you try a factory reset, with the on board reset button?
Yeah I tried a factory reset (and again just before I replied just in case!!!) and no luck. The annoying thing is that I have 2 antminers that I got at the same time (Batch 1) and updated with the same firmware but one works the other doesn't....
Thanks for the advice though, I think I am going to try running both off 1 controller for now
Sorry to hear that. Some people in Batch 1 got different batch miners. Might be the hiccup. I don't know if the S7 controller has a SD card slot that it is configured to boot from if slotted in. You could check that but if not i don't know how you could unbrick it.
Since the reset button does not work, i think philipma1957's verdict is exact.