Panasonic NV-HS960 - worn heads?
 

I bought this VCR on eBay a few years ago (back when this stuff was < €100, thankfully), and have never been too impressed by the picture quality.

One particular issue I noticed when recording this test video:

https://www.youtube.com/watch?v=ZLevxHUnaj0

In areas where there are solid vertical black and white bars they are often accompanied by horizontal noise (comet tails?). It's not seen as often with normal video/film content but does happen occasionally with bright high-contrast graphics.

Also this was played with the TBC on, but there's still a lot of jitter (if you play at 1080p you'll see the edges more clearly). Is this normal behaviour of the TBC in VCRs like this? This is consistent with how the TBC works with normal video content on this VCR.

I don't have a captured example, but S-VHS playback has constant snow (the same tapes play fine on my JVC HR-S7000EG) and is pretty much unusable.

I have tried cleaning the heads (with head cleaning sticks and IPA), but it hasn't made much difference. Is there anything else that could be at fault?

Even more disappointingly, it looks like replacement heads (VXP2050) are no longer available for this unit (I contacted Donberg and they are no longer able to source it), whereas they are for the HS950 and older decks.