Panasonic omnivision vcr problem
 

Hi,
I'm hoping you guys can help me out here.... I just bought an older Super VHS VCR Panasonic VCR from the late 90's... I have another one just like it (same model) but the one I got recently has some issues, was hoping you'd help identify. I have uploaded a couple of 1 minute videos, links below.. I have correctly cleaned the heads prior to use (as I do for my other VCR's), so I'm not a total newbie at this. I have hooked up the VCR with the issue identically to the other one (which works fine). The problem is as follows: (1) you'll note in the 1st video that all I'm doing is switching channels (tape is not inserted) and you'll see what looks like some kind of interference in the background (between channels). Again, I compared the same other model VCR, similarly connected and it's fine so I know it's only this one that has the problem. Every input / output causes the same problem. The 2nd video shows me playing a recorded tape (that I taped off cable) - see the same problem but seems to be more pronounced also on the black/white movie at the start, like waves of streaks.. (Again, the heads were manually cleaned very well using paper strips and 99% alcohol until no dark oxide was present...). This problem occurs when watching TV through the VCR and also when something is taped. So I see this as NOT a recording problem but something else but as you can see is significant. Pre-recorded cassettes seem to play fine though.
Another problem is that whenever a tape is inserted and is otherwise playing or FF or REW, an onscreen prompt displays "no cassette - please insert a cassette" (even if cassette is playing etc..). It doesn't seem to affect the playback or anything but why is it showing up? Are those two things related to some kind of electronic problem?
Here are the videos, thanks for viewing:
https://youtu.be/kp-yNOjsDOo
https://youtu.be/LHKSyBb2Yks

Any idea of what this could be?
Thanks again.

It looks like failing capacitors to me. Have you ever done soldering before? To replace capacitors you need to know how to solder and observe the polarity when replacing electrolytic caps. A $15 Chinese ESR tester off ebay will make IDing the culprets easier. I'd start on the power supply section and see if that does it.

Remember to remove the caps from the circuit before testing them or you will get false readings!

With the tester, I recommended the caps don't falsely test good in circuit, but instead will sometimes give false bad readings...If they test bad again after removal that confirms the issue.

The ability to test in circuit (VCR unplugged) and the cheapness are the two reasons I favor those testers for this type of work.

If you get an error that says "no cassette - please insert a cassette" when a tape
is in the machine, then it seems that one of the many sensors that detect a tape
is in the machine may not be working. And believe it or not, this error is likely
to be there even after you replace every last capacitor.

A quick search on G with your quoted error turns up a few pages from various
VCR repair sites. You can also ask G "Panasonic VCR Troubleshooting" etc.
and you may be able to get closer to a good description of what your machine's
problems are.... Use the words other people are using to narrow your G search.

If you really have 2 identical machines then you have a known good one for
reference. So look around inside both together. Also, why not post a video
of the known good one too so we can see the difference.

It seems like your machine's troubles may be in the tuning/IF or some switching
problems. You may have a single problem or 2 problems.

.

Recap the switching power supply. Especially the secondary side.

Thank you so much to everyone who replied. I'll be sure to update this thread if anything changes. By the way, the Panasonic model is PV-S9670. I only bought it 'cause there is no other VCR that I own (some are even more higher end) that has the quality of picture that the Panasonic has of this era (and that's in standard VHS mode). Too bad that I seemingly have a dud on my hands.

So that there's no misunderstanding, I've attached a few screen captures which best represent the problem - the smudges, blotches, waves etc...

It certainly looks like you are having some noise that is a harmonic of the horiz
sync frequency. Almost repeated perfect vertical lines. This could be from the
osc. in the rf output box in the vcr, it is pretty much should be a small self
contained box, you may be able to turn it off, or switch channels see if it changes.

As for the power supply, open up both vcr's set them both up and compare
voltages from random points in the power supply. If you have a audio tracer
stick it to a few points see if you have noise where you should not. 15Khz might
be audible.

Just because you get the noise from line out, and RF out does not mean it still can't
come from the rf out box. Just cut off the power to that small box.

Look for bad grounds, previous work on the machine etc.


.

Oh boy, Username1, sorry, I didn't see your reply there. Year old thread but thanks anyway. Never got to working on this problem too much but I'll give your suggestion a try.

The problem could also be found in the S-VHS processing video PC board, with failing surface-mount capacitors on the IC chip.