[BrianG]

As you said, the steering servo still has power so you know the batteries, bec in the ESC, CH1 on the receiver, and all wiring in between is fine. That leaves CH2 on the receiver, the ESC motor output, the motor itself, and all the wiring in between as the problem.

You could also check the red jumper on the ESC. I don't remember what the ESC does if it comes off or has a bad connection, but it's something to look at.

Usually, it's a bad connection somewhere. Even though everything looks ok, you could still have a bad solder joint on the motor connectors.

Does the motor beep when the system is powered up?

If yes, the ESC is probably ok, but it could still be a connection issue since it requires a lot less power to beep the motor than to drive it. Resolder the motor connectors or directly solder the wires together.

If no, then you could have an ESC or motor problem, or a connection problem.

Between the motor and ESC, I would suspect the ESC first since that is where there is a lot more things to go wrong. The motor is just a bunch of coils. If one coil burnt out, you should still see a little movement on the working coils.