Anyone got any suggestions on this one? A friends got a v3.1, it was working fine but then stopped, it started going in the final after someone pushed it from the line but then stopped mid race.

It turns on automatically when plugged in and has a red light. I've had a look, it is still factory soldered, so unlikely an issue with bad soldering etc. I connected it up to the PC and successfully flashed etc so it is somewhat working. It's been tested with two motors but doesnt go.

He said he very briefly connected up reverse once but only very briefly and worked fine for 5-6 meetings after that. It doesnt smell burnt out and looks perfectly fine inside the case.

Any possible suggestions on a fix?