I have the same problem

I dont know what to do
Yesterday I've had found a problem with one of my miners (S7). It started to make a sound (internet connection problem, I supposed) but it was only one of my seven antminers, I thought "this is rare" so I enter in the interface and everything looks good and then I reboot the miner... The sound stop and in the interface everything looks good for the first minute and then the GH/s started to go down until 0 and the interface stayed forever thinking, they won't showed me nothing more, just thinking and thinking.
Things I've already checked:
1. I've changed the PSU, same problem.
2. I've changed the router, same problem.
3. I've changed the IP address, same problem.
4. I've changed the miner network from dhcp to static, same problem--> when I restart the miner it let me do some things until the GH/s arrive to 0, then I can't do anything. So I have to act quickly.
5. I've change the IP address reservation from my router, same problem.
6. I've changed the BB and IO board, same problem.
7. I've had made a few hard resets, same problem.
8. I've already sent an email to
info@bitmaintech.comI don't know what else to do.