VCR squealing + unstable playback — traced to supply-side tension arm (back tension issue?)
Hey all,
I posted previously about playback issues on this deck and I’ve done a lot more troubleshooting since then.
At this point I’m pretty confident the problem is related to back tension on the supply side, specifically the tension arm / felt brake.
Symptoms:
Squealing noise during playback (worse in fast reverse, almost constant there)
Picture is unstable in normal play
Picture is stable in FF/REW scan
After cleaning, playback improved slightly but not fully
What I’ve done so far:
Cleaned video heads (properly, not a cleaning tape)
Cleaned tape path
Identified the supply-side tension arm as the noise source
The felt brake was black/glazed, I cleaned it with 99% IPA
It’s now back to a lighter/white-ish color
Pulled a lot of oxide off (swabs were coming off very black)
Rubber Renue applied to the pinch roller (brought back grip)
Oiled capstan
Current behavior:
Squeal is reduced but still present
Still consistently squeals in fast reverse
Playback is only slightly improved
My current theory:
It seems like the tension arm is applying too much or uneven back tension, possibly because:
Felt brake is worn/glazed beyond recovery
Or pivot/spring isn’t behaving smoothly
Questions:
Is this consistent with a worn tension arm felt brake?
Can the felt be restored further, or is replacement the only real fix?
Would improper back tension alone cause unstable playback like this?
Anything else I should check on the supply side?