When accessing the one with the problem, the main page (miner status) never loads anything, but is weird because the miner is responsive, I can access the other web pages: overview, firmware upgrade, pool configuration, etc. But in the pool it shows as not hashing.
The first thing I would want to eliminate would be the possibility of a browser issue, use a different browser to access the status page to check if there is any difference, you could also use a free monitoring software like AwesomMiner just to check the status of the miner with that issue, now once you confirm that it's indeed an internal issue, here is a list of the things you can do.
- Take out the control board and put it in a different miner to see if it acts any differently.
- Flash an older firmware version (probably not accessible unless you contact Inno's support.
If all fails, then chances are your control board is out and you need to replace it.
What is more important is to find out why would all your miners restart, there could be an underlying issue causing them to do so, and what happened to this miner could happen to the rest, have you figured out the reason for the mass reboot?