Ferndale, i had a TX that eventually lost throttle controll - it was very intermitent and barely worked. i took the TX apart and found that the copper contact plates that the sticks move across had started to wear out badly and were dirty. took the sticks apart to get the the little PCB that had the copper contacts and cleaned it up and after that it worked just fine. only took a few minutes, and you'll know if its worn out, there will be a groove in the copper.

nick