I have dozens of servo motors operating in a project called "Santa's Shop," and one servo joint developed the "jitters" or "shakes." I replaced the offending motor and that restored the operation to normal.

Now that it is summer, I decided to examine the jittery motor and see if I could restore it (as a spare) and I found an easy cure for the shakes.

Step 1:

Remove the four screws that hold the motor shell together.

Step 2:

You are trying to get to the feedback pot, which is usually located beneath the circuit board.

Step 3:

With the board lifted (on my servo), you can see the pot.

Step 4:

Remove the screw that secures the pot.

Step 5:

Locate the tabs that secure the back of the pot.

Step 6:

Using a small screwdriver, bend the tabs so that the back of the pot can be released.

Step 7:

This looked a little worn and dirty, so I cleaned it with a readily available safe cleaning wipe (toilet paper--good for cleaning black stuff). Yes, I wiped it with plain old toilet paper (two ply) for about ten seconds.

I reversed the process and put the servo back together--now it works like new :)