On 18 ene, 20:13, "Chris F." wrote:
the problem is that the tracking slowly and
constantly wanders back and forth. I tried tweaking some of the adjustments
on the servo board, but still could not completely stabilize it.

AAAARRRGGGHH! the phantom twiddler! A pet hate of all techs! I HOPE
you marked the original positions of those pots.....

I admit my
knowledge of VCR's is somewhat lacking; I never fully grasped the concept of
servos and PG systems and much of the other complicated circuitury.

....and still you hope to refurb and resell these beasts? I would
forget it if I were you.

I can
only guess that some reference signal is drifting in frequency, but that's
about as fancy a theory as I can come up with.

.....that is not even a theory, that is pure guesswork. have you
checked the A/c head? pinch roller? tape path? torque? consumer
tracking adjust pot condition?all of these are fundamentals and well
known causes for this problem....

B.