CP-16R Crystal Sync Motor Drift

[Geffen Avraham]

Hello. I've recently been testing the speeds on a CP-16R I've been repairing. The camera runs, although the "test voltage" button does not work, and it "stutters" a bit when stopping. I do not think there is any corrosion on the PCB. During 24fps operation, the light turns off and it seems to function well.

However, when testing with the "video tachometer" app, the speed seems to very slowly drift. It is much, much slower than the drift at non-sync speeds - it's barely noticeable unless you wait a full minute, but it does drift!

How might this be happening? Does this ruin sync-sound use? Can it be fixed? Below are videos of the shutter motor at 24 fps vs non-sync 32 fps.