Servo doesn't work when plugged into elevator channel

I'm back....

I had a bit of an incident that caused a servo to fail, so I ordered a new one and it didn't work. I plugged the servo into a different channel on the receiver and it worked fine.
What had happened was I accidentally allowed the rotor disk to strike something while it was spinning and it jammed the servo arm around.
Is there some kind of failure detection in the receiver that I need to reset? I have the walkera m120d01.