Will a JVC VCR "Stop" Playback if the video is "too grainy" or degraded?

[timepassenger]

TL;DR: Will a JVC VCR "Stop" Playing a Tape if the video is "too grainy" or of very poor picture quality even if you know there is more content (video) left on the tape?

Hi, I've got a JVC S7600U VCR for transferring/digitizing old home movies. I think I've found an issue with the VHS tapes that are older (or perhaps not stored properly).

It seems like the VCR will be playing back the tape, then get to a part it "doesn't like" and stop. I'm still trying to narrow this down to specifics.

As an example: I have a VHS tape that is from 1986. Like most home movies, it is a hodge-podge of different events; whenever someone decided to pick up the camcorder and press Record. So you go from Easter 1986 to some random cookout in the summer to Thanksgiving to a Birthday Party, etc. etc.

I was playing this tape back while capturing with VirtualDub, and I noticed that the VCR just stopped and the time counter stopped. I looked at the output file, and it seemed like once the VCR got to a section of tape that had a lot of distortion (rolling picture?) / grain / bad quality it stopped. At first, I thought it was simply the end of any recorded video on that tape.

But, I tried again. This time, the VCR continued to playback further than before, and I found an entire family event on the tape that, before, the VCR hadn't played the first time!


This has happened several times. And sometimes I can fast-forward the tape in the VCR to skip ahead and 'see' if there is anything on the tape. And sometimes, I can fast-forward the VCR, and it will stop, all by itself. And then, with the SAME VHS TAPE, other times it will continue to playback further than before.



My only theory (and it's probably silly) is that the VCR has some sort of threshold, and if the video quality isn't high enough, it stops. I have turned on and off the TBC/NR feature on the VCR and still get this issue. (I was thinking that having TBC turned on might raise the 'threshold' for acceptable noise and the VCR was like "Uh, no, I can't even tell if this is a decent picture or blank tape and static; I'm just gonna stop right here.")


To me, my theory is sort of like digital error correction: If you have a digital signal with few errors, they can be corrected or simply ignored without interrupting the stream. But eventually a signal could be degraded so much that the device / software simply can't deal with that many errors, and just stops playing.


Is there anything to this? Am I going crazy? If this IS something that others have experienced, is there a way to force the VCR to simply continue playback, regardless of picture quality? Regardless of if the tape goes from picture - static - picture? To keep playing even if it goes from good, stable video to bad video (because there might be more good video later on the tape)?

Thank you in advance!

[oln]

It shouldn't stop just by the video signal being bad. VCRs will however usually if the tape is physically damaged or if there is too much resistance when trying to pull it around the tape path.

[dellsam34]

Either the tapes have mold, sticky or the VCR has a mechanical problem.

[timepassenger]

Thanks both of you!

So, I don't know about mold. The outside casing on the VHS tapes seem clean.

Also, regarding the tapes being damaged or if there is too much resistance: that COULD be. I guess all I can do is to try again. Like I said, sometimes the VCR will stop by itself, and other times (same VHS tape) it has continued playback.

I only recently started in on the VHS tapes (was doing the 8mm tapes) so I don't have a lot of data points to go off of.

If it turns out to be a bad VCR, UGH. I wouldn't know how to diagnose that, and me taking it apart to look at the drum unit, motor, gears, whatever is a bad idea (because there WILL be extra parts once I put it back together! Oooop)

[timepassenger]

It shouldn't stop just by the video signal being bad. VCRs will however usually if the tape is physically damaged or if there is too much resistance when trying to pull it around the tape path.

Ok! So, the only time the VCR should stop on its own is if there is something wrong with the tape (or the VCR has a mechanical problem) So at least I can eliminate the possibility of the VCR 'detecting' a bad signal and stopping.... right?

[orsetto]

So, the only time the VCR should stop on its own is if there is something wrong with the tape (or the VCR has a mechanical problem) So at least I can eliminate the possibility of the VCR 'detecting' a bad signal and stopping.... right?

Right: VCRs don't have any sort of "brainpower" that detects badly recorded video and engages stop mode, so you can rule that out.

You will eventually trace this to one or more of the other causes that were posted above:

1. The JVC has gone wonky and needs repair (not exactly unknown with this type of VCR).

2. The VCR has the "scene stop feature" enabled (for lack of a better term: I forget what its actually called because I never used it). This is an intentional feature you can turn on and off via the menu, to have the VCR stop at every new recording. Not common, but if if your VCR has this and it is turned on, it will stop at each new recording or section where the camcorder originally stopped and started.

3. The VHS-C to standard VHS adapter shell you are using is defective, causing unusual tension or drag that triggers the VCR safety stop mechanism. Try another adapter shell.

4. Your tape(s) have a physical problem which is triggering the VCR stop mode. While the myth of "VHS rot" is largely untrue (I have many tapes dating to 1980 that still play perfectly), your specific combination of tape brand, age, and storage conditions may have led to issues.

If stored unplayed for years in a hot climate, the ribbon of tape can get sticky and make the reels drag, triggering the VCR mechanical fault detector to stop it. If the tape is inordinately sticky from humidity, mold or adhesive decay it can damage the VCR. DIY tape treatment options are discussed on DigitalFAQ, but for most people such tapes should be written off as goners unless you're willing to pay a pro to salvage them.

Very long term unplayed storage can lead to the overall tape cassette simply being sluggish: same result. That is why its often recommended to fast forward and rewind the tape before attempting capture (to maximize smooth operation, you can additionally let the tape play normally thru the end, and rewind once again prior to capture, which re-forms the tape pack on the reel as evenly as possible).

5. The tape is seriously mangled at the points where the VCR stops. Since you say the tapes may have sat in the camcorder for months or years, started and stopped, each new recording session could have yanked or twisted or creased the tape: many VCRs will stop if they sense that kind of damage to protect their video heads.

[lordsmurf]

If from eBay, I'm not surprised.
This is a common problem with some models, when not in proper functional condition.

[themaster1]

Maybe it has something to do with the auto calibration feature of the JVC deck (it check tension of the tape continually i believe) , i know you can disengage it, can't remember how though.
You may have to disable the TBC/NR feature aswell

[dellsam34]

It's a mechanical problem, It has nothing to do with any VCR feature. The fact that he mentioned the video gets too grainy and the VCR stops, that's a good indication of a VCR screwing the tape, Possibly the take up reel stops moving due to worn belt or idler tire then the VCR detects the fault and the protection mode kicks in to stop the playback. Since he didn't even bother to pop the cover open and observe the event I assume he can't fix it, he should start looking for another VCR there is nothing magic we can do from our end.