The chip itself has an overheat threshold which is around 130's C. If the chip shuts down, the chain breaks cause the whole the unit to basically shut down from a hashing perspective. If you're using putty, you'll see an error message similar to CMD_READ_REG ERROR. If you see this, unplug it, wait 30 minutes restart it via putty and do the following:
root
amt
killall cgminer
cgminer -DT
And check to see if the cores in each chip are ok.
Also there are two 4-5 fans in this case. There are two 140's under the cage blow air up through the fins. The 200mm exhaust on top and the 120mm x 1 or 2 in the front of the case blowing air in.
So...if you have 2-4 restarts like the highlighted one and you are looking at 1-2 hours of downtime daily plus that you need to monitor the thing the whole fucking day. AMT you must be very proud of your work.
I have both AMT and Cointerra miners in my farm. I have similar issues with the cointerra as well. All of sudden cointerra boards just drop and i have to power cycle the unit. same crap.
I have not had a board drop on my AMT. I have had to power cycle since a board didn't come online, but once its running it running.
I my miner has the old cage. I run it with the side panel off and do not have any over heating issues. I have seen the new cages when i was at AMT and they are soid, but there was an issue with the holes. AMT is working to get miners out. When i was there a Fedex freight showed up and picked up a pallet of miners going out to Michigan.