Originally Posted by philipa_240sx
A sticking/faulty servo that is drawing excessive current could definitely cause issues like OP is describing. Definitely check the RX voltage with a DVM.
Thats a good point. Take a look at page 7 of the attached PDF file in this thread:
Sometimes those electronics have a problem when they've been on for a few minutes and things start to get hot. Along with that the current drain jumps. Good way to check for this is to power it up for 10 minutes with the digital meter monitoring current, and make certain that current drain doesn't change when the servo is not being moved.
Shot in the dark, but its fairly easy to test for.