Streaky pciture on Panasonic S-VHS machine

[Eric H]

I picked up this AG-1980 Commercial model Panasonic today during the half off sale, so it was $10.

At first it wouldn't do much of anything, it would attempt to load then shut down with an error code, figured out that was gummed up lube on the shaft the pinch roller slides up and down on, a drop of Ronsonol freed it right up and it began loading and playing, however the picture had some terrible streaking, it made it look like it had 1/4" scan lines, I tried cleaning the heads, I tried putting gentle pressure on the back of the tape to hold it against the heads better but that made no difference.
I finally just let it run and after a while I looked at it and it looked pretty much normal shut it down and changed tapes and some of the streaking came back, not like it was but bad enough, I suspect it would go away again if it played a while so possibly something thermal, possibly some bad caps somewhere or maybe the brushes in the rotating head are dirty?

I don't think it's the heads themselves since it doesn't have any static or dropouts and tightening the tape with a finger makes no difference.

This is a pretty nice unit with Time Base Correction and other goodies, it would have a really good picture if it was working properly so fixing it would be nice. Any ideas?

[old_tv_nut]

I really don't know, but maybe it's a connection / grounding problem somewhere? I guess I would try tapping / pushing on / re-seating connectors and printed circuit boards. Are you coming out composite video (or S-Video) or RF? If composite or S-Video, try exercising/cleaning the RCA or S-video jack.

[Eric H]

That pictures was using the Composite output but it looked the same with S-Video.

[Eric H]

Here's another example.
It's actually watchable but it's annoying on darker scenes.

[centralradio]

Nice catch Eric. That deck was the workhorse of the day .


Some Info here .


http://forum.videohelp.com/threads/3...-1980-NV-FS200

http://forum.videohelp.com/threads/3...0-chroma-noise

I think this is for the PAL deck but the mechanics should be the same.

http://elektrotanya.com/panasonic_ag.../download.html

[Electronic M]

I believe I got one of those at the fall ETF meet. I need to get to testing and fixing that one.

[Ed in Tx]

Bad electrolytic capacitors. Probably has a bunch that are failed or failing.

[Eric H]

Well if it's just electrolytics then there's hope. I wasn't going to mess with SMC's.

[Ed in Tx]

..including any surface mounted electrolytics. (I think that's what you meant )

Motor noise, power supply noise, microprocessor noise.. get out your ESR meter and start hunting them down.

[Dude111]

Wow a 1980 player Erik??


Good luck getting her running good again