From your pool records, did both units stop mining at exactly the same time or different times?
Sorry for the late reply.
Yes, they were connected to the same main phase. And they just stop minning in different times. I have 4 ebit miners and 2 of them just got burned.
Once plating is worn off the connections become very warm and things quickly avalanche down hill from there. Reason the data cables fried is because after you lost the return paths from the hash board plugs the next in line to (try) to carry the high current were the data cable returns.
In short - just 1 more reason to be very wary when buying used hardware...
Thank you for your answer, I'm sorry for the late reply. I agree with you, these miners were used before, maybe the original owners didn't treated the miners very well...