I had something like this happen when I was doing some maintenance on a CX2. I swapped the motor leads going into the 3-in-1. Mind you, the polarity was corect, so the blades turned the right way, but the plug that was supposed to be on top was on bottom and vice versa. She would spin like mad, I was kind of able to calm the spin, but she still wouldn't fly. Swapped motor leads and all was well again. Just something else for you to try...