JVC HR-S9x00U shutdown after initial play? Non-DD causes?

[aramkolt]

Hello all,

I've got an HR-S9600U that I'm working on and it's basically acting like it has a bad DD (dynamic drum), however, I've already disabled that and the gears turn well when the DD motor has 5V applied in either direction to the the motor when tested outside of the unit and I can hear it turn when DD features should be working as well as at initial startup.

I've also thoroughly cleaned the mode switch.

It'll power on and play for a few seconds, but by the time "Video Calibration" would be done flashing onscreen it shuts down instead. During that short time of play, the picture looks fine. It'll stay on a little longer if I do regular FF or Rewind, but it still shuts down after a few additional seconds.

I've tried multiple known good drums and different DD units in it and the symptoms remain the same. This unit also appears to be pretty low-hours and all of the capacitors in the power supply area are testing good. I've also reflowed the board connectors for the deck, though they looked good to begin with.

The only thing I think I noticed being a bit odd is that the head drum does not spin on its own at initial power on, which most VCRs do, but I haven't verified that 9600U's are supposed to do that.

So my question is, what else can cause the system to shut down after playback initiation like that outside of the mode switch and the dynamic drum?

[latreche34]

Check all CP fuses (circuit protection), they are tiny black components, they look like transistors but with only two legs, their purpose is to blow first if there is a mechanical problem to protect a motor or a solenoid from overheating or causing further mechanical damage. One of my decks did just that after disabling the DD system, however in my case the head would not spin at all and the VCR shuts down after few seconds, replaced the CP component and everything came back to life.

[aramkolt]

I will definitely look into that. Thanks for the suggestion!

[kimblerulez]

I have a 9700EU being delivered. At this stage I'm pretty sure that the DD system is OK but it seems that by it's very nature it will eventually fail. Has anyone managed to create a successful repair of the system, i.e. mould a new gear? There are plenty of YT videos on "How to" If not, maybe it is time that we start a collab project here?

[latreche34]

The design of those gears with metal in them makes reproducing them a very challenging task, 3D printing is out of question, The large ones do crack but the ones mostly responsible for VCR shutdown are the small ones with metal core, the crack can get bigger than a single tooth and cause the system to jam up and throw a code for shutdown, Even if you manage to make them, inserting the center metallic piece will be a challenge.

Since they are not responsible for normal playback, it is not a bad idea to remove those two small gears and leaving the big ones in place to provide motor pulses for the control system to avoid the shutdown..

[aramkolt]

Agree with latreche34 - I've had several units where the DD worked fine, but I'd consider it prophylactic maintenance to disable/remove the DD gears as it does not affect playback whatsoeverever and can lead to a lot of problems. Those issues will probably pop up at a not-very-convenient time, including after having sat for months or years without being used at all.

The other issue is that leaving the DD system in place increases that odds that the transverse shaft to the motor develops a crack on the gear that is driven from the middle by the DD motor. I've seen that be the cause for maybe 1/3 of all DD failures. At best, you'll get a clicking sound when the DD motor moves, at worst, the crack makes a space wide enough that the worm get gets jammed while driving it and prevents the mechanism from moving at all and you'll get the usual symptoms of shutdowns etc. None of this is good for the DD motor either which we need to work so that the different sensors "see" that it is moving to tell the VCR that everything is ok with the unit.

I'd be a little surprised if there weren't some sort of jumper on the board that could be made to just tell the system to ignore the dynamic drum or perhaps that is something that could be done with a service remote? I know it was never meant to be a user-disableable thing, but seems odd they'd make a VCR that has a feature that some models had and that some didn't that couldn't be made to be bypassed electrically.

The machine that might give ideas on it would be comparing say the 9900 vs the 9911 (doesn't have dynamic drum), or comparing the 7600u to the 7800u (doesn't have dynamic drum). If the DD can't be electrically disabled, it's certainly possible to just trick the machine into giving the readout it is expecting to get from the DD unit with an arduino wired to the board taking in and giving back the appropriate signals that the VCR is wanting to see so it thinks things are ok, but I'm not smart enough to write such code for an arduino unfortunately. Soooo mechanical bypass it is for now.

Even if you could make new gears, it would still cause stress on other parts in the DD unit that is unnecessary for playback, so I wouldn't recommend that either.

[latreche34]

Quote:

Originally Posted by aramkolt

I'd be a little surprised if there weren't some sort of jumper on the board that could be made to just tell the system to ignore the dynamic drum or perhaps that is something that could be done with a service remote? I know it was never meant to be a user-disableable thing, but seems odd they'd make a VCR that has a feature that some models had and that some didn't that couldn't be made to be bypassed electrically.

The system control has to see a pulse from the motor, It's not as simple as putting a jumper somewhere otherwise I would have done it already. I don't know what community to reach out to about this, maybe Harrym from the VHSdecode or someone with such coding skills can make a small board with a custom code to mimic the pulses when the system control asks for it, This also should answer your question about the difference between a DD and non DD VCR, it's all about the firmware inside the system control chip.

My hope is we can someday be able to make those gears and be able to control the DD motor externally for problematic tapes, such as tapes with shrinkage or stretch problems where the recorded tracks no longer have the right angle, this is problematic for low speed tapes, SP tapes are forgiving.

[lordsmurf]

Quote:

Originally Posted by latreche34

maybe Harrym from the VHSdecode or someone with such coding skills .

Warning.

I'm not aware of Harry having any coding skills, as the vhs-decode project was largely written by our own hodgey.

Harry is a very hostile and immature 22-year-old, and I would not suggest others engage with him. He rants about quality S-VHS gear, preferring to buy his low-end VHS VCRs from thrift stores, maybe even rescued from dumpsters -- and it's likely because he's basically unemployed, according to his LinkedIn (see attached image). The "documentarian" of an open-source project is essentially an unpaid intern.

I highly doubt he's ever used or owned any recommended/quality TBCs or S-VHS decks.

He constantly rants about me, this site, others using quality gear, etc. In fact, anybody that disagrees with him is "the enemy" or "the other". We live rent-free in his head. It's very odd. I suffer from all sorts of health issues, life limitations, but I'm nowhere near as miserable as he apparently is. He's such an angry person, that I can imagine he spits when he talks. (I'd love nothing more than to be a healthy 22-year-old again. Sometimes youth is sadly wasted on the young. I sure as hell wouldn't waste my time being an angry keyboard warrior.)

Just another person wearing money blinders. For your own sanity, do not engage, ignore. He'll try to convince you that recommended/quality JVC S-VHS decks (with line TBCs) are the worst ever, and some Funai/whatever POS is better.

[latreche34]

So he is just a cheerleader? According to his Github page makes it sounds like he is a big contributor to the project. So who's making the new vhsdecode boards then? He is the only one talking about them.

[lordsmurf]

This is getting too off-topic.

However... <sigh>

Quote:

Originally Posted by latreche34

So he is just a cheerleader? According to his Github page makes it sounds like he is a big contributor to the project. So who's making the new vhsdecode boards then? He is the only one talking about them.

Correct, the head cheerleader, right out of Mean Girls.

The official Github for vhs-decode is oyvindln. That's not random letters, but literally Øyvind L. N., the user we know at VideoHelp as oln (member since 2019), and as hodgey here at this site (member since 2017). When hodgey came to this site 7-8 years ago, he was a young(ish) video newbie that really took an interest in video/TBCs/VCRs/etc, largely due to his then-new day job. He's intelligent, cheerful, kind, easy to converse with.

hodgey is one of the few users (that I know about) that knew less than I did when starting, but has exceeded my knowledge in some areas. Teacher love to see that!

Øyvind/oln/hodgey is basically the anti-Harry.

Harry, on the other hand, tries to insinuate that he is responsible for vhs-decode, and anything in it's orbit, which is ridiculous. hodgey/oln was working on this back in 2018 or 2019, when our young Harry was still a teenager in high school, completely oblivious to analog videotape capturing. It wasn't until the pandemic, in 2020, that our bored Harry got online, and started to "chase clout" as a self-proclaimed photo expert. But his clout attempts at Quora and Wikipedia failed, and he went unnoticed. Then he apparently took an interest in video, found the infant vhs-decode project, and somehow convinced hodgey/oln to let him run the Github account by 2021 or 2022.

So Harry is really a newbie at both vhs-decode, and at video in general. It's very obvious that he's spent hours pouring over my literal decades of online writings, as he very often repeats my very unique non-jargon phrases and descriptions.

Honestly, the entire situation is sad. I had approached hodgey/oln back in 2019, offering to host the project here at digitalFAQ.com, with a dedicated project wiki. I was interested in blending the existing quality of VCR/TBC/capture gear, with potential software-side advances of vhs-decode, in order to get the best possible from tape -- especially as it related to inferior-gear formats like Betamax/cord. But he declined. So what we've ended up with instead is a project that usually creates inferior VHS "captures" (as compared to quality gear, not thrift-store crap), and essentially gear-less formats are still ignored. vhs-decode was the solution to a problem that didn't really exist. The real problems were ignored.

I've long said it could long-term be vaporware, as it makes promises (especially wonky ones from Harry) that may never attain fruition. The project needs more reality, and less BS. I don't know who he thinks he's fooling. Sure, other rank novices, but not video gearheads. The current setups are "duct tape and chicken wire" in nature, and nothing is easily replicable. Actual viability, beyond proof-of-concept, or low-quality expectations, is still likely years away, if ever.

The anti-spend mentality also hobbles the project, as dedicated hardware will be required to ever succeed. On that front, the project has relented (MIRSC, etc), but Harry refuses to acknowledge that I was right all along. Which brings us to your comment about vhs-decode hardware. Perhaps Harry finally learned something, and is applying it. But from what I know, he's merely the fluffer and cheerleader for others. For example, MIRSC was made by somebody else, not him, though I forget all the details now. But when reading him, you'd think it was completely his invention. That'd be as daft as me taking credit for manufacturing DataVideo and JVC gear. Why all of these people have let Harry take credit for their work is a mystery.

Most people don't know any of this. They just buy into his smug immature BS, and never question it.

The ironic part here is that, if he wasn't such a twit, we'd probably get along great. We have some similar interests and hobbies. I actually find it neat that he appreciates tape and film.

Well, now you know, as well as anybody else reading.

To steer this back on-topic now...

Quote:

Originally Posted by aramkolt

I've got an HR-S9600U that I'm working on and it's basically acting like it has a bad DD (dynamic drum),
It'll power on and play for a few seconds, but by the time "Video Calibration" would be done flashing onscreen it shuts down instead. During that short time of play, the picture looks fine. It'll stay on a little longer if I do regular FF or Rewind, but it still shuts down after a few additional seconds.

Perhaps slippage within the transport. Did you verify all gears and belts, not just DD?

Quote:

I've tried multiple known good drums and different DD units in it and the symptoms remain the same. This unit also appears to be pretty low-hours and all of the capacitors in the power supply area are testing good. I've also reflowed the board connectors for the deck, though they looked good to begin with.

Like any other test, you can get false positives. You're potentially running into an unstable power issue, and the JVC solution to any problem is to shut down. It could still be power board caps. Unlikely, but tests can lie. When you run down other issues, sometimes you need to circle back in the troubleshoot to address these possible false test results.

Quote:

I've also thoroughly cleaned the mode switch.

I've written it before, I'll write it again...
Cleaning the mode switch rarely accomplishes anything, aside from wasting time, and falsely hoping it's not something else. I don't understand why "clean the mode switch" has become the new "clean the heads", as if it's some sort of fix-all to heal whatever ails a deck.

Quote:

The only thing I think I noticed being a bit odd is that the head drum does not spin on its own at initial power on, which most VCRs do, but I haven't verified that 9600U's are supposed to do that.

I'd have to test each deck (something I don't have time for now), but I do recall some JVCs do not power on the head cyclinder until the tape ingest begins. I'm guessing it's just not part of the POST. All of the JVC decks seem to POST slightly different, especially the various SRs.

Quote:

So my question is, what else can cause the system to shut down after playback initiation like that outside of the mode switch and the dynamic drum?

Loose connections, power issues, sometimes mainboard fried/glitched. I've seen all of those multiple times over the years. Some can be fixed, so are door stops.

Quote:

Originally Posted by kimblerulez

Has anyone managed to create a successful repair of the system, i.e. mould a new gear? There are plenty of YT videos on "How to" If not, maybe it is time that we start a collab project here?

Actual molds will cause $$$$, so we're left with shoddy 3D printer options that will definitely fail in a short time.

I'm all for videos, but written documentation tends to be an essential sidecar. It needs to be both. Youtube allows too much rambling, going too fast (must repeatedly REW video), hands in the way, etc. I vastly prefer community-organized documentation, and the slick video can come later.

[kimblerulez]

A JVC HR-S9700EU has just arrived and is in pristine condition with the DD system in working order. I am in Australia and not sure whether this model was ever sold here. After reading all of the above and much more about the DD gear failures I think that I may have made a mistake. The gear that seems to fail is made of both metal and plastic which will both have different expansion and contraction rates. This machine has come from Europe to a hot climate sometimes over 40 degrees. What is the consensus of opinion over the failure reason, is it different expansion and contraction of the materials or just the aging and breakdown of the plastic?

[lordsmurf]

Quote:

Originally Posted by kimblerulez

What is the consensus of opinion over the failure reason, is it different expansion and contraction of the materials or just the aging and breakdown of the plastic?

Yes, all of those.

[kimblerulez]

Quote:

Originally Posted by lordsmurf

Yes, all of those.

I suppose what I'm asking is, is it worth the expense of setting up a climate controlled enviroment for this particular machine in view of the bi material gear or will it just give way anyway. Do any not break or is it inevitable?

[latreche34]

It is too late, not much you can do now, just enjoy it while it lasts, but most importantly don't mess with it until it starts to give you problems.
Basically the plastic over time shrinks due to age, the metal center core doesn't, so the plastic will crack. These machines where not designed to be used for 3 to 4 decades, The only reason we still use them is because the sheer amount of recorded materials these VCRs left behind, on top of that most of us didn't care about transferring these materials when these VCRs where in good working order or at least it was possible to get them fixed locally, In the last few years a lot of people trying to get their tapes done.