Similar issues guys.. R4 Batch 4.. After multiple restarts it stopped hashing on one board - It was working 'perfectly' at the start. After firmware update back to both boards but now on the affected board, there is no temp display. I am going to try a factory reset later today. It seems Bitmain are more concerned with getting your Bitcoin than with the quality of their releases. Just FYI I'm using an APW3 PSU which Bitmain confirmed would work prior to purchase.

The reason I put perfectly in commas is because the when the R4 started up at first, it would not hash.. It wouldn't detect the firmware but instead reported 'Socket Error - Connection Refused'. It still does this but exactly 8.5 minutes after boot, it detects the firmware and starts hashing.

Very messy Bitmain!