JVC HR-7100U: Heavily distorted picture

[ESigma25]

I spent my day today working on my JVC HR-7100U, after finally getting the belts I ordered almost a month later. But it has a problem, a real nasty one.

This is what the picture looks like when you play a tape:

https://i.imgur.com/yXywhpF.jpg

It's black and white and constantly rolling and trying to adjust the tracking knob on the front of the machine just makes it worse. I've already cleaned the heads on this VCR at least three times and I do get sound perfectly fine, so what's stopping me from getting a stable picture? I can't even find a service manual for this VCR anywhere to see if there's a tracking adjustment on one of the boards in the machine.