I bought a used Revo 3.3 with the TQ radio (high output). When you initially power on the receiver & transmitter, the servos work. Shortly afterwards steering, throttle, and shifting don't move. It's as if the link is gone. There's also a noticeable hum/buzz. A friend of mine has a Revo he bought new and mentioned he has a slight buzz/hum with his as well.

I tried pulling the opti-drive and going direct to the receiver. Same issue. I also tried one servo at a time. Same issue.

I had a funny thing happen before I noticed the issue. It involves loss of link, no failsafe, and a Revo at half throttle headed towards a natural gas line. Apparently I'm a faster runner than I thought.

Any ideas on how I can pinpoint the actual issue? Thanks.