I used to have a GT3b transmitter on my powerboat, and loved it. I have now purchased a new GT 3C transmitter set up, after 6 minutes the enter button stopped working, so being a handy person with electronics i decided to trace the fault.
It turned out to be the switch that fits under the wheel, an smd microswitch, the others on the radio are same as. I de soldered it and tested it, it proved to be duff. Not having another one, i decided to swap the one on the bind setting to use that, as i had matched the tx and rx.
Result all working ok, I was well pleased.
I then a few days later wanted to put a new flysky receiver into another car, and use a seperate channel, however after 10 mins of programing and setting servis etc, the Entry button stoped working again. On testing another microswitch had failed. Due to the fact i had been in to sort it out, and quite frankly its been the worst transmitter i have ever had / seen, i took my flustrations out on it and trashed it. It was a week old, but i had been in it so couldnt handle trying to justify myself with the chinese sales company.
I now await a new gt3b transmitter, the last i had was superb. Avoid the GT3C if you possibly can.
Total Garbage.