That sorta happened to me on a maiden flight of a Vector flight xtra 300. Just rolled left and I couldn't do anything. All my radion stuff seemed to be alright but I didn't trust the servos again, even after sending them in for a chek up. Now I let the rx run for a least a minute before take off on a new charge. Just to pull a little juice out of the batteries. I replaced them with Hitec mg digitals. 645s.