Photon 2.1 ESC problems
 

My nephew has an FTX Carnage and he's having trouble with the ESC (Photon 2.1w), it came working fine but after two runs it wouldn't give any throttle input. I recalibrated and now I get forward, but no reverse. If I adjust the throttle trim on the TX I get reverse but forward doesn't work properly. I followed the instructions for "throttle range calibration" in the manual. Any ideas?