The chips on hash board seem to fine. One hash board's hash rate drops 0 suddenly. Does anyone have any idea?
I recall having this problem on a R4 unit from their first batch. I never figured out what was causing it, but eventually that hashboard went offline permanently and quit working. I left it alone as numerous complaints about the R4 failing were pouring in, and it just didn't seem worth the expense of shipping to China. Several months later I sent it to BitmainWarranty (in Colorado, USA) and they had to replace the board as one of the chips had gone bad. If it wasn't for the BTC price spike I probably wouldn't have bothered fixing it.