Recently purchased 2 x S17+ 70TH, April batch but delivered in May due to delays at Customs. Both machines worked fine initially, then dropped a hashboard. One machine after just 1 hour and the 2nd unit after approx. 2.5 hours, very disappointing Spent several days back and forth with Bitmain support doing everything they asked but to no avail and now both units have been shipped back for repair.