What country are you located in?
can you try 1 hash PCB connected to the control instead of all 3?
If you are in USA, you can ship the whole unit to Denver, Colorado to be diagnosed what is going on if you cover the shipping fee.
I have an S7-F1 that is acting strange. I can ping it with no packet loss and I can access the web interface but whenever I try and click on the miner status tab it just hangs. All other tabs function normally. I also am having ssh issues, I get an RSA key prompt, and I am able to input my login but it just stalls and never asks for the password. Odd thing is when I brought it in for diagnostics with no boards connected I am able to access the status page without issues. Has anyone seen anything like this? I am still troubleshooting but I figured I would throw this up in case anyone had seen this behavior before.
