JVC VCR malfunction after sticky tape?

[lordsmurf]

JVC SR-V101

It was fine.

I put in tape. It was at end, not beginning, needed REW. But the tape struggled to move from one reel to another. Slight squeal and pulling sounds. Tape doesn't move properly. Eject, inspect. Tape seems fine, problem is probably cheap shell.

Re-shell, try again. Still struggle.

Next re-spool to new reels. Put leader onto new reel, manually moved from old reel, while in new shell.

Manually advancing, it seemed to move much more easily after half moved over. So reassembled tape, put in VCR, hoping to quickly REW rest to new reel. Started to fast REW, then saw tiny amount of oxide shed. Then started to squeal/pull again, before I could stop.

Stop, eject. Manually move rest of tape to new spool.

To verify VCR still fine, put in test tape. When inserted, it momentarily squeals while loading. REW fine, FF fine. But play pulls and squeals. Tape starts to slack in transport, so now brake in question too.

Took deck apart, inspected, nothing stands out. (Well, needs some cleaning/maintenance, but nothing that should cause squeal/pull.)

Put back together. Hooked up to capture card, preview how play looks/sounds. Now unit ingests tape, makes tick-tick-tick sound, shuts off. Few attempts to turn back on, press eject, spits out tape.

I'm tired, I'm pissed, I want to throw something. Stupid tape broke my VCR.

Ideas?

[themaster1]

Sounds bad the way you describe it , tick tick sounds and stuff.
You know the drill, amongst other things: check back tension , also check the idler/clutch to see if there are no cracks on the gears. Cracks on the idler gear or sticky = no play/ff/rw guaranted -> eaten tape shutdown possible aswell.

Next step could be to clean/resolder the 2 photos sensors of the takeup/supply reels on the board

Got a scotch tape just like that, messing my gear

[radiokom]

Relax, nothing is spoiled. Perhaps you got Video tape with sticky shed syndrome (SSS). Now do nothing, I will come back a bit later and explain this problem end solution (if you need to digitize this tape). For now carefully with IPA clean all VCR parts what came in contact with tape. Visually they can look clean, but they are not.

-- merged --

Here are some info about SSS:

https://favreaumixingmastering.com/e...ent-tape-list/

As noted in this and other publications, some video tapes are affected too, not only audio tapes.

However picture on top of this article is completely wrong - BASF tapes was never affected by SSS.

-- merged --

So, I know most of audio tape SSS and dehydration procedure, but not much about video tapes, except the same reason - polyurethane binding. Here is one article where Ampex VHS is mentioned:

https://internationalvideotapecopy.c...sional-baking/

Because we (at least I) do not know how VHS tapes should be baked because there are no technical info (there are Ampex bulletins and many articles about audio tapes), I would advise to use food dehydrator. I use it for audio tapes instead of baking and got good result. And there is less possibility to spoil something because of incorrect temperature regime. Because you do not need to "bake" them, but only dehydrate and baking in thermo-controlled ovens was only way to dehydrate tapes before food dehydrators became widely available. Of course, after dehydration, you should digitize it immediately, because after 1-2weeks it will be back with SSS. So dehydration again

For example - Ampex Grand Master 456 tape affected by SSS can completely stop Studer A80 with all rotating guides and tape contact with fixed area only at heads/dummy heads. So, after tape affected by SSS, all parts should be cleaned carefully, even rotating parts, including capstan, pinch roller, rotating guides, heads.

This is what, most likely, happened with your VCR. I do not believe VHS cassette affected by SSS can damage VCR. Maybe something can crack (plastic parts for example if they are brittle) but it depends on particular machine. I am pretty sure, for example, Panasonic K-mech would survive.

[lordsmurf]

I don't care about the tape, just the VCR.

I've dealt with many deck issues, but this exact issue/symptoms is new.

It's extra frustrating, because that's the deck I was about to use for another project, and now I can't. I always have alternatives, it's just not as ideal as the V101 was here.

I'm mostly pissed at myself, I never should have tried to wind the tape in the deck. I knew better, but did it anyway. I was trying to save myself time, and the outcome is more time now needed (and probably some funds, too). So let this be a lesson to others: don't be impatient, it will cost you (in time, or money, or both).

Still soliciting suggestions on what this could be.

[radiokom]

Did you carefully cleaned all transport - guides, head drum, heads etc.?

If, after careful cleaning, it still does not work and ticking sound remains, probably it is toothed timing belt. Just remove transport and inspect it. I doubt something else can be damaged.

[lordsmurf]

The V101 is a simple design, two screws to remove the transport cage, unsecure the rear IO, and the whole board lifts out. (In some ways, it's a great design. In others, not so great. Like everything else, using it in a workflow takes some planning, not randomness.)

I didn't see anything wrong on the teeth.

This unit is/was like-new in many ways, and I bought it at least 7 years ago, maybe even 10 years ago. It's my realign deck, sometimes my "dirty deck", because it can be cleaned fairly easily. I've not dismantled it for at a least a year now, and I can see it needs some attention to lube/grease.

I'm hoping it's not a motor somewhere, but I'm not convinced it is.

After dismantle, a mystery spring came out of it -- the kind you find in VHS tape shells, or JVC doors. I don't think it belongs anywhere in here.

[radiokom]

Try too look at transport parts list (attached) and diagram to find your mystery spring.
I believe this transport is the same as in yours? I did not found in 101 manual transport layout but it is in 82911 manual, also attached.

Perhaps spring is Nr. 113 or 116?

[lordsmurf]

Nope, not 113 or 116. It has a perpendicular L-shape to it. The L is the same length as the two sides of the spring. It looks like a slightly smaller black version of the spring that swings the deck tape gate. I don't think it's part of this deck, as I heard it rattling under the mainboard when I started to remove screws. It was have taken some lucky bank shots to go from on top of the board (in/on the transport) to under the mainboard. There's not a lot of clearance. I wanted to mention it, just in case, but I don't think it's related.

I don't think a spring is causing tick-tick-tick or the pull/groan on the tape.

The tick-tick-tick sound seems to come from near the heads, while the groan sound seems to come from under the right reel (tape gate facing you). Under that reel is the "rotary encoder". But also under that reel to the front side is the loading motor.

But it loads, REW/FF -- just not properly pull tape without struggle in play. And then the head areas is "tick tick tick" amd the head stops now.

This back-and-forth troubleshoot is helping.

I'm almost tempted to lift everything out, and run a tape without the case. But it'll be some days before I can setup a working area for it.

[radiokom]

Perhaps cracked gear somewhere. Forces on transport, when rewind tape affected by sss are huge. So in this case possibly the weakest link in the chain has failed somewhere in reel drive chain.

[lordsmurf]

Quote:

Originally Posted by radiokom

Forces on transport, when rewind tape affected by sss are huge.

Yeah, I just messed up, and now I'm down a deck.

[radiokom]

I wonder if there are cheap JVC with the same transport to swap mechanic or take as donor? Only transport I know really well is Panasonic K-mech, and they are available (with minor differences like loader upper plate what can simply be replaced) in many cheap VCRs. So, if NV-HS1000 fails (however they all are repairable except if someone tried to "repair" it before - than you need to replace mechanic) you can buy cheap VHS in mint condition for EUR 50 with composite output and replace mechanism or use it as donor for necessary parts. JVC transport looks simple for me.

[lordsmurf]

Quote:

Originally Posted by radiokom

I wonder if there are cheap JVC with the same transport to swap mechanic or take as donor? Only transport I know really well is Panasonic K-mech, and they are available (with minor differences like loader upper plate what can simply be replaced) in many cheap VCRs. So, if NV-HS1000 fails (however they all are repairable except if someone tried to "repair" it before - than you need to replace mechanic) you can buy cheap VHS in mint condition for EUR 50 with composite output and replace mechanism or use it as donor for necessary parts. JVC transport looks simple for me.

Yes. I'd need to verify, but likely the 2901, 2902, 5901, 5902. But not $50 each, more like $200 each if working.

[radiokom]

I would search for not working. Transport (part of that) is all what you need, other do not matter.
Like that for $40 with no power on:

https://www.ebay.com/itm/236181044974

If mech is damaged too (unlikely), throw away and buy another "for parts". Why pay for working VCR? Keep fixed audio heads, replace drum and something else if needed and you are done.

[themaster1]

If that can help you as far as "springs" go, this is on my jvc combo HR-XV3 (that i still need to fix)-> see picture
Looks like the same mech with a cheap front loading cassette holder/lock system (2 screws to remove it), not like that on jvc svhs decks hr7xxx-9xxx.

[radiokom]

Did you found the cause of the problem? For me this mechanics looks simple and service friendly, if it is similar to 7722.

[lordsmurf]

I get busy -- and at times, hardware errors can easily frustrate me.

But I finally had some time to dig into the service manuals, take apart the deck, take some pictures.

Service manuals can be so worthless at times.

So, in review, the deck quit working after an SSS (sticky shed syndrome) tape was inserted. At most, we're talking 30 seconds of the tape being in the deck.

Upon pulling it apart, this fell out:

JVC SRV101 spring NK86935.jpg

Once the entire transport was removed, and flipped upside down, I saw a spring that looked very similar:

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See it? Look closer:

JVC SRV101 underside NK86928 web.jpg

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But it's not the same -- and obviously not missing. So where does it go?

(FYI, the full-sized out-of-DSLR image is attached in a 7z file. Enlarge as desired.)

In fact, what even is that spring?
The service manual completely ignores it! On pg2-9 of the 5901 service manual (SM), figures 2-2-7b, it's just missing:
(NOTE: The SR-V101 service manual is merely an addendum to the 5901 SM, as the chassis share many parts.)

JVC SRV101 underside NK86928 crop web.jpg

So ... WTF?

In fact, it's labeled as the "tension arm lever", but I don't think that's correct.

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Admittedly, I don't remember the name of every single piece in a VCR. But still.

Now then, the SR-V101 manual break-out diagram shows the spring, and labels the two parts.

69  LP10400-001N  CONTROL PLATE
70  LP40843-001A  TORSION SPRING

JVC SRV101 underside NK86928 crop web arrow.jpg

It's also not "50" from the diagram, which is drawn badly, an in actually about 2x larger. Also not 113, 116 or 128, also 2x-3x larger than drawn. (This diagram is NOT to scale!)

I'm just at a loss here.

I wish I had a good/working unit to compare it to, but do not. (I'd even considered buying a deck from eBay, but nothing I see there is tempting, so many red flags, and several known-bad sellers. The eBay VCR market is hosed, especially for this deck model.)

And yes, radiokom, the underside grease is a mess. One step at a time!

At this point, I may need to assume the spring is not even from this deck, and another issue entirely is at fault. I just really don't know.

I'm "this close" to sending the deck to a certain member here, to get a second opinion.

[radiokom]

I believe pinch roller spring (44) is in its place (hard to imagine how it can fall off of course)?

[lordsmurf]

Quote:

Originally Posted by radiokom

I believe pinch roller spring (44) is in its place (hard to imagine how it can fall off of course)?

44 is a huge spring, and the pinch roller looks fine to me.

I need to reseat the round thing.

JVC SRV101 SM round thing.jpg

NOTE: I may fix VCRs, and know what I'm doing with the stuff inside. But it's not like a vocalize the names of all the little widgets and doodads in my head or aloud. And it's not the most interesting topic of conversation, so I never discuss it IRL. And then I also don't really discuss refurb/repair much online either (I can do, or discuss/teach, I just don't have time for both), so also no typing.

Add in MS, getting older, and .... what the hell is the name of that thing again.

EDIT:

Found it in another JVC service manual. Rotary encoder.

This thread makes brief mention of them, and the common failures on JVC VCRs.
https://forum.vcfed.org/index.php?th...-vcrs.1250026/

Quote:

In later generations of VCR's they moved to a rotary encoder on the mechanism to tell the CPU what position(condition) the tape transport is in. These rotary encoders in many VCR's became notoriously intermittent and resulted in failure of the tape transport in many models and some service companies fixing VCR's would replace the rotary encoder off the bat with any sign of tape transport malfunctioning.

Seen it, many times now.

I hope that's not the problem here.

[latreche34]

Be carful with SSS tapes, It's a silent death for VCRs, most of the time cannot be seen by eye since the bonding layer that goes bad is underneath the magnetic layer, so it's hard to spot.

The only possible location for that spring is shown with the arrow blue, I don't see any other possible location where it can be, Is it an extra spring from a previous repair job from another guy that got dropped and never found? Ticking teeth damage is hard to see with naked eye, I would use some magnification and replace the faulty component, a tool that most techs don't take seriously that helps pinpoint the location of the ticking, A stethoscope, very cheap for what it can accomplish:

[lordsmurf]

Quote:

Originally Posted by latreche34

Is it an extra spring from a previous repair job from another guy that got dropped and never found?

I don't think this deck had ever been opened by previous user(s). I'm not fully aware of the history/lineage of this deck, but it seemed OEM to me. Even the screws were tight to a "machine inserted" tolerance. I doubt somebody was using a torque screwdriver on it. So this may be an OEM factory "extra part".

It was wedged somewhere, as the unit never made any noises. When I buy a "new" (to me) deck, one of the first things I do is gently shake/tilt, listening for broken parts. Sadly, plastic clips are often broken in transit, usually due to poor shipping. Those clips can be a nightmare to tapes and/or decks, if not removed.

For now, I'm going with the "extra parts" hypothesis, and moving on to reseating the rotary encoder.

Quote:

Originally Posted by latreche34

a tool that most techs don't take seriously that helps pinpoint the location of the ticking, A stethoscope, very cheap for what it can accomplish:

You're right. I'll get one.

Amazon has everything from $5 to $500. Suggestions?