Then of course, as mentioned above, the RMA on an S9 is pretty much a joke ... so you gotta hope your S9 never fails ...
One of my two S9s had one hash board stop working. After some research I found I could get it replaced for about $600.00 . At the time the S9 was selling for under $1200. Needless to say I have mined on with only 2/3rds of one of my S9s. I probably should buy a 1000 Watt power supply to power the 2/3rd S9 and free up its power supply for use with a 741/761/A8.
This is voodoo - had a couple S9's with same problem. One board (always chain 6) either dead or missing chips on reboot.
This works for me - not sure why?
Turn off all power for a few mins
Reboot with
no internet connectionLet it cycle for about 30 mins - it will start up and shut down repeatedly.
Connect internet.
Magic - it runs for about 2 weeks above 13.5TH/s.
Sometimes repeat a couple of times till you get the correct performance - be patient - wait at least 24 hrs till you decide.
If GH/S(ideal) for chain 6 (or any chain) is in the 2k range - repeat immediately. All 3 chains should be above 4k.
Then eventually (after about 2 weeks with 100 x HW errors of the other 2 chains) chain 6 board goes down over a couple of hours in GH/S(ideal) to the 2k region.
Just repeat and it recovers - all good for another couple of weeks.
I'd be very interested to know if it works for you - and if anyone might have an idea why?
NEVER return your miner to Bitmain China (via Hong Kong) on warranty - they take over a month and send somebody else faulty shit miner back - dirty full of mosquitos from Taiwan, not fixed and with same chain 6 problem. Its just a Swaparoo (an Aussie term that CAN mean just keep moving things around, look busy and trying to help - but don't do anything useful). Support goes DEAD eventually if you keep complaining that your WARRANTY replacement has the same problem you started with.
Cheers - usukan