Crazy servo chatter with old Hotshot 2 MSC

[Wandy]

As the title explains, I'm in the process of knocking up a Hotshot 2 runner out of a collection of old bits 'n pieces and have got to the electrics stage. When I connect the battery to the circuit without the motor hooked up the servos operate just fine but when I connect the motor wires the servo controlling the MSC is all over the place, resulting in the motor and transmission going crazy. It responds to forward & reverse commands as normal but simply cannot hold a fixed position without chattering away, meaning the car would have a life of it's own if I actually tried to run it.

Any idea why this might be happening? I'm guessing that the receiver has a fault with it's BEC, resulting in voltage spikes that makes the servo chatter. Or maybe the MSC has a fault? Anyone had this problem with Hotshot MSCs before?

[billg4]

do you have capacitors on the motor and it's leads?

Also, be sure the motor brushes are good, and not burned.

Check the MSC contacts, use a pencil eraser to clean any tarnish or if bad burnt use fine sand paper

[WillyChang]

try a different servo & RX independently

not unknown for old electronics to get waterdamaged, just from condensation being sealed in their crate after damp running

if 540 runs very hot whilst glitching, it may have 1 pole shorted out

[mr crispy]

What you've described sounds just like I experienced with a bad servo. Try swapping the servo out first to see if that's the problem.

[Wandy]

Well in the end I just swapped the whole RC system for another one and the MSC servo now works fine so the problem wasn't with the MSC itself. Will try the "defective" servo/receiver on another car and see what happens.