Although most VCR's appear to have only 2 mains feed-wires, I found that earthing the cover of my JVC HR-J657-MS via a cover-screw to a cold-water feed eliminated occasional noisy video streaks that would appear on playback or recordings.
Whether this was outside interference or internal noise is unknown, but it worked.
The electrical earth-wire was run from bathroom (hose-clamped to bare-scraped steel pipe) to my lounge earth-bar-hidden-behind-a-sofa, intended for a soldering ground-point.
EDIT:
As for the tracking, my limited VCR work would suggest that you may have mis-aligned heads beyond limits, meaning you would need signal generators and/or oscilloscope etc to re-align again.
This may involve taking it in to a video tech.
Somewhere in my collection of books and scans, I have notes on VCR service, so if I come across relevant info, will add another post.
Perhaps other members are more VCR tracking savvy than YT....
