I feel pretty stupid. They tested it before they returned it, which means they had to have linked it to another controller. So, yes, I had to relink to mine. Works perfectly. I will say this - the response I got from DJI when I first contacted them about the cracks was immediate, and cooperative ( it was still under warranty ). I packaged it up, sent it back to them as per their instructions. They received it last Monday by UPS, I got an email on Tuesday saying the repair was done, another email on Weds. saying it had been tested, and another on Thurs. saying it had shipped. I received it yesterday. No charge, no questions asked. I did order a set of 4 reinforcing plates to mount under the motor mounts. Anyone tried this, or any other ideas on beefing them up?