we are sorry to hear that, it may be a time for the Control PCB unit to be replaced. Could be the control PCB itself or it could be the beagle bone or combination of both.
However, once in a very while... the MicroSD card physically goes bad. We have seen a few cases where simple MicroSD card replacement from a local store (kingstone or Sony 4GH) took care of the problem.
if another MicroSD card doesn't work, please proceed with the parts replacement via warranty. support @ bitmain . zendesk . com
Thank you
I would say this is prone to happening, and with the S2 Ive replaced the SD card twice. Other RPI/BBB-controlled ASICs (BTCgarden, rockminer, bitfury) all have the same problem - SD cards dont always handle reboots or power 'blips' well.