How was the service dealing with China directly? I imagine it isn't too late for me to email them instead of the US team.

I am impressed the way Bitmain handled my warranty claim. I sent an email to info@bitmaintech describing the issues I was having, only 1 out of 3 boards worked out of the box. Wrote order number and problem on the subject line. Also added type of power supply I was using, in this case a Bitmain 1600 watter, sent a picture of input voltage with a  voltmeter just in case.  Got a reply from Sherry Liu, she asked if I opened the miner yet, if not open and inspect. I found loose heatsinks and burn marks on the boards after opening up the miner. I sent pictures to Sherry. She approved the RMA and sent me prepaid shipping labels. Note because of time difference it is not fair to expect a reply within an hour or two, wait at least 24 hours or longer depending when you sent your email. After shipping out the boards, replacement boards were at my doorstep in 7 days. I ordered more than 10 S7s from Bitmain and this is the only S7 that gave me trouble, they are all hashing at their advertised speed or faster. Also it is good to be polite, I am sure Bitmain didn't mail a defective miner, things get rough during shipping.