Fastest solution would NOT include sending the whole unit back to Bitmain. Anything but that!
Short version: Bought an R4 Jan 2017
Sent to hosting facility
Ran for a week then one board craps out
Sent back to Bitmain for warranty repair - $$$ shipping cost
Came back a month later
Ran for a week then one board craps out again
Sent back to Bitmain for 2nd warranty repair - $$$ shipping cost
Bitmain will not repair R4, offers replacement T9
I ask for S9 instead due to similar W/GH as R4
They agree and state will ship Oct. 2017 - it is now Aug 2017
Actually shipped end of Nov. 2017
What a waste of time and coin...