Technobeam color wheel problem

I've got a technobeam giving me trouble with the color wheel.

It would not home. The wheel would not spin or sometimes seemed to stutter as it spun or tried to spin. I replaced the motor and it now homes correctly but will loose home after a revolution or two of the color wheel in the self test. It won't make the full transition to the next color. (fails short rather than over shooting) I've also tried swapping out the control chip for a spare which had no effect. I checked the wiring between the board and the motor; it seems fine and I had continuity on each pin. Do the brakes ever fail in a way that makes them stiffer? I did check that the wheel is not tight to the brake.

Any suggestions would be greatly appreciated.

Thanks,
Mat
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