I have read several threads here and wondered if anyone could help.

I've got a GT3B controller that I bought secondhand. I also have another controller bought new and several receivers (all GR3Es).

The new controller works with all receivers, no problem.
The used receiver binds just fine but loses connection (as in receiver light flashes and doesn't respond to steering/throttle).

Right now the controller is sat 3 feet from the car and its disconnected. If I put it next to the car (within 6 inches) it will connect and work fine.

The really weird thing is that earlier today it was working fine, at a guess the car was 100+ feet away and working fine, I drove the car back to me and whilst at my feet the radio started to play up again and it had no range.

I've just powered it up here and the radio was far enough out of the way, same thing, then it started working with the controller maybe 20 feet away, now its playing up again and the controller needs to be right next to the car.

As I said, it won't matter what receiver I use (note: different car, different esc too) I get the same problem, but only with this controller.

I have had the controller apart and found that the aerial wire wasn't connected very well (I suspect someone has had it apart before), so re-soldered it according to a thread here titled "Broke antenna wire Flysky GT3B - Any suggestions" (cant link due to post count currently).

Does anyone have any ideas ? I doubt if it would make a difference, but I haven't found a reset for the controller yet (when I got it there were settings in it for the previous owner's cars)., there there one ?

I suspect the answer is going to be throw it in the bin, but I thought it'd be worth asking.