Panasonic NV-FS200 PB flashing streaks

[carduelis]

Hi!

Can anyone give me some advice why these streaks appear during playback?
Maybe also some bad capacitors, but which ones or does it have another cause?

Regards
carduelis

[ben]

Earthing strap on the drum is loose, most likely. On the Panny S-VHS machines we used to use at uni, though, it was an early sign of head wear.

[Welsh Anorak]

Please don't be tempted to change capacitors. This is unlikely to be a capacitor fault and is probably exactly as Ben says.

It's possible some capacitors will need replacing at some point, but beware anyone who advises blanket 'recapping'.

[carduelis]

Thanks for the quick replies. The earthing strap was still solid screwed. I took it off and cleaned it. A short test looked good and I hope it will stay like that.

[carduelis]

Did not last very long

[HamishBoxer]

Trust the heads have been carefully cleaned? If so, warning of wear.

[dj_fivos_sak]

Hi. This looks more of a drum earthing problem rather than worn heads. Usually when the heads start to wear, you see such streaks around high-contrast areas such as subtitles over a dark background. If you put the machine into pause/freeze frame, do the streaks stand still or do they dance around in random spots of the picture?

Fivos

[Welsh Anorak]

The fact that you managed to get it working shows you're on the right track.
I'd check all earthing screws just in case there's static build-up.

Back in the day we used to connect a flying lead to chassis and use it to temporarily earth the head drum as a test when we had this kind of fault.

[dj_fivos_sak]

Glyn

When I faced a similar problem with a Sanyo Beta machine, what I did is I connected a piece of wire between the drum and the metal RF shield of the head pre-amp assembly. It worked like a treat and hasn't acted up again since. This is easier to do on a Beta since the upper drum doesn't spin so I am not sure how one would do something like this on a VHS machine with a spinning upper drum. Perphaps connecting the lead to to stationary lower drum instead would cure this issue?

[carduelis]

I was now able to look after the VCR again.

During pause the streaks dance around, but I have the impression that they always appear in the same lines.

They don't appear permanently, they sometimes disappear for a few minutes.

I connected also the head drum with a flying lead to an earthing screw at the top of the PSU-case, but it didn't help.

Surprisingly, it makes no difference if I run the machine without grounding bracket (and without flying lead).

I also borrowed the PSU, head amplifier and grounding bracket from a flawless, identical Blaupunkt RTV950. Didn't help either.

I hope my attempts don't end with a faulty Panasonic and a broken Blaupunkt.

[its ur aerial]

I would also suggest bad earthing or head wear, this was all fairly common on Panasonic VCR`s, also you could try gently increasing the tension on the Back Tension Arm,
Ken G6HZG.

[davph30]

Check SQPB in the menu is off or auto

[dj_fivos_sak]

What about swapping the entire head drum assembly from the Blaupunkt? I know it's quite dangerous to do but it will rule out a worn head or possibly a fault with the rotary transformer.

[gallowfields]

Originally Posted by davph30

Check SQPB in the menu is off or auto

would second that recommendation ,i always switched it to the off position .
brian

[whaka54]

hello,

i think you're fighting against bad dropout compensation.
when i say bad, i mean all DOC aren't great, no real solution except "deal with it".

see an exemple from a panasonic MS4 s-vhs camcorder, playing a vhs with tracking set a bit off, just to show :


there's nothing to do, it's not a fault, just the way it works...

[dj_fivos_sak]

Originally Posted by gallowfields

would second that recommendation ,i always switched it to the off position .
brian

The NV-FS200 is a real S-VHS machine with no on-screen menus, just a S-VHS on/off switch on the front panel that won't have any effect while playing back regular VHS.

[John123]

Looking at the fault list for the NV-FS range of machines, there are a few mentions of the odd capacitor or dry-joint giving similar problems.

I know it's a bit of a long-shot, but perhaps try giving the PSU and component-side of the boards some (gentle!) hairdryer treatment. If it's a bad cap, the fault might just clear (albeit temporarily) when sufficiency warmed-up.

[HamishBoxer]

Knowing NatPan as mentioned, I have had a lot of odd ball faults caused by secondary psu caps.

[bobbyball]

I had a problem with bad playback/streaking in a Grundig S-VHS machine (Panasonic deck). It turned out to be bad caps in the power supply too. Pig of a board to get to!

[whaka54]

hmm... ok, maybe i spoken too fast on this one...
i join myself with this issue, even if it's a camcorder, it's still a panasonic of the same era after all