What are these blue artefacts on dark scenes?
 

Hello,

I'm in a PAL territory. I got a Panasonic NV-FS100 for cheap and it's a nice S-VHS machine even if it has no TBC, but it's showing some blue diagonal stripes on some dark scenes where my cheapo LG LV3793 does just fine. Same thing on the Pana S-Video and Composite output, see examples. Attached also settings used on Pana. What gives, is this some usual issue that I'm not aware of? Is there a fix?

This looks like chroma noise. Try turning on the noise filter in the Panasonic, if that doesn't help you can try some denoise filter in post-production.

No, fix the VCR instead of masking the problem.

Yeah, it looks like chroma noise, thanks for the reply. I'll play around with the settings to see if the results can be improved.

What is the issue with the VCR, what components need fixing?

It could be anything, this is something a qualified technician or hobbyist can figure out with the right diagnostic procedure, I'm pretty sure it is going to be in the chroma or the power supply but I don't have the VCR in front of me so it's hard to guess.