JVC VCR chewing tape? (Philips VR-1100)
 

My Philips VR 1100 (I think this is a clone of the JVC HR-S7700) VCR (PAL model) has developed a problem where it eats tapes, and I’m trying to figure out the exact cause. This is a Philips VR 1100, which is essentially a JVC clone of the HR-S7700.

Watch my YouTube video to see the problem (I would love to embed it into this post, but don't know how):
https://youtu.be/STxQeruBolg?si=hUjF0DMZMalVxYmU

The problem gets worse with longer tapes:
- Shorter 1–2 hour tapes (E-120) usually play fine without being damaged
- Longer 3–4 hour tapes (E-180 to E-240) almost always get chewed up

What I’ve tried so far:
- Cleaning the tape path (not the video heads) with cotton swabs and 99.5% isopropyl alcohol
- Cleaning the drum and video heads with chamois swabs
- Replacing the pinch roller with a brand new one

I would really appreciate guidance from anyone who knows these decks or has dealt with a similar tape chewing problem. Any repair tips, adjustments, or common failure points to check would be very helpful.

I don't have much experience with video cassettes, but I do have solid experience with audio cassettes.
After watching your video, I can identify at least three possible reasons why tapes might get eaten:
1. The take-up reel's pull is too strong.
2. The pinch roller is applying too much pressure on the capstan.
3. The pinch roller and capstan are no longer coaxial - possibly because the capstan is no longer vertical due to wear.
As for why only longer tapes tend to suffer, the answer is fairly simple: they use thinner tape.

Hard to tell from the video since it just appears to crinkle out of nowhere, but my guess is it needs a pinch roller replacement based on what I'm seeing. You have nothing to lose by trying to clean the pinch roller better first though since there's visible residue on it. If the mating surface with the capstan isn't exactly flat or if there's some issue with the bearing, it could intermittently pull the tape up or down potentially causing what you see there.

Hard to see. Try lifting the flap up as high as possible without damage to give a better view. Perhaps chock it up temporarily.

I would like to agree with opinion that something is wrong with the pinch roller alignment relative to the capstan shaft. Pinch roller wear alone should not be a cause. Or back tension is too weak (but in this case there should be another problems too) Maybe one (or both) of the guides is also out of place. In such cases, simple adjustment will not help - a mechanics full test according to SM is needed. And this requires a number of tools that used to be in every repair shop, now few have them (Tentelometer for example). I would recommend simply replacing the VCR, it will be faster and cheaper.

Thank you very much for all your great suggestions. It's highly appreciated :congrats:

Here's a little update:
I've now made an updated video by playing a special made tape without the flap to better show what happens. I've tried cleaning the brand new pinch roller with isopropyl with no improvement :hmm:

But I've made a new and probably important discovery: If I change the angle of the audio head, then the problem is gone. But then the mono audio gets distorted :question:

Here's the new updated video: https://youtu.be/jpieWyojkuU

hysteriah, applying aggressive materials to the pinch roller is not good idea - the rubber gets degraded.
Yes, by tilting the head you just compensate the pull. It is not a solution, it's just temporary workaround.
Your problem will keep worsening.
Before you throw your VCR away, try to tilt the block with the pinch roller towards the capstan.
If you over-tilt, it will start pulling tape up, under-tilt - it will keep pulling it down.

It is a myth. All studios around the world always cleaned pinch rollers with IPA and heavy dirty with acetone. How would you imagine roller cleaning? With baby soap? :)

Not a myth. Reality. I saw many of them becoming soft and sticky.
Yes, soap would be much better.
Acetone? That's the best way to destroy them. Well, maybe after a flamethrower. :)

Clearly there is a problem with mechanics. If heads are fine, I would try to find cheap, dead (no power on), JVC with the same mechanics in ebay, take mechanics, swap head cylinder, keep fixed heads from new transport. You are not able to repair mechanics and most of repair shops are not able too. And if any, it will cost more than 2 fully working VCRs. Do not mess with it.

No! I have more than 30 years experience on studio tape recorders. Do not use polyurethane, like those Athan crap, what are sticky even when new. Normal rubber rollers should be cleaned with IPA. An when get used gear at first service it is normal to clean roller with acetone.

Just for the sake of the arguments I asked google "Does acetone affect rubber?"
Short answer was "Yes".
The same for IPA.
Both OK for short term, occasional use. Not good for long term/regular use.

And from where you know IPA make rubber rollers soft and sticky? From google too? :) You should know - rubber rollers never goes soft and sticky, but dry out and became hard. Than you know (after 10 years of use, not 24/7 of course) it is time to send roller to Gianni from Sofh.it to rerubber. It is polyurethane what goes soft and sticky. And those should be avoided, because they are crap.

-- merged --

From video looks like that guide after capstan is bent. But I am not sure.

You are tilting the head back. This is the head zenith angle. The head's face must always be perpendicular to the chassis. There is only one correct angle. Without the correct alignment tool it can be difficult to get this 90 deg. angle right. Pushing down makes the tape run higher up the head, where it probably should be. But it's not that simple. Tightening up that back screw a certain amount will fix the problem but may cause another. The tape pressure on the head may now become uneven. Either the audio or the control track signal may be compromised. Long term head wear also compromised. These are not toys.

For example, that's how you start fires. Ask me how I know. :smack: :laugh:

Always remember:
- If something "nothing to lose", for learning, go for it.
- If this is a mission-critical piece of gear, do lots of reading, and consult with others, before attempting the DIY fix. And realize it may be some you have to pay others to fix (which even I do at times).

Exactly what do you consider short term and regular/long term use in this manner? I mean, nobody cleans their VCR's on a daily basis, not even weekly or monthly. Me myself, I probably clean it about yearly with the VCRs that I use most often. So if the rubber on the pinch roller can handle 10 times cleaning with alcohol, it will still last for 10 years. I don't mind replacing the pinch roller every 10th year when the rubber has dryed out and hardened anyway ;-) But thanks for letting us know your opinion about it :-)

This is the kind of reply that I appreciate A LOT and are very greatful for, thank you very much :-) You obviously knows what you are talking about and you give me valuable advices of what to do (or NOT to do) along the way. That's how I can learn and understand this better :congrats:
I am perfectly aware of the fact that I am messing with things I don't understand, but with this particular VCR I feel that I've got not much to lose. It's pretty useless anyway, as long long as it's eating almost every tape I throw into it :mad4: BTW, I haven't touched any of the 3 adjustment screws for tilting the head yet... I've only applied just a littlebit of preassure with my finger, so I don't think I've done much damage to it yet. :rolleyes:
Do you agree with other suggestions here in this thread, that the problem most likely is with the capstan and pinch roller not hitting each other the correct way? Or do you have any other suggestion of what might be wrong?

Only your time, spend for nothing. Maybe it would be better to spend it with beautiful girl, not that thing? ;)
Anyway you can not repair it. And even if you (with axe and crowbar method) will get it to not skew tape (at least visible with bare eye) mechanics will be out of alignment completely anyway. How you imagine to calibrate it? Replace mechanics and remaining time spend with a girl :)

Well, I can't really come up with a better definition of "wasting time", than spending it with a girl... haha :laugh: ...but thank you very much :congrats:

And if about pinch roller cleaning. In those days when studio tape recorders was used every day and pinch rollers cleaned with IPA few times every day they last about 3-5 years without problems. Then they was simply replaced. Now I send them to Gianni from Sofh.it to rerubber on original core (the best quality in the world, Terry Witt in US may be an option, but professionals send their rollers to Italy even from US). Of course, no one rerubber VCR rollers, they are available NOS if needed (but it does not mean they are all the same quality, if not original). So clean with IPA and sleep peacefully. :) But pinch roller is not your problem anyway.

Every time you use harsh chemicals on pinch roller it damages it. I don't see any reason why it has to be done that way. Easier? Maybe. Anyways, it is up to you.

Yes, I've never experienced any problems by cleaning my pinch rollers with IPA. I've done it for many years, but just for home useage, not professional. I have a bunch of VCR's that I switch between so I clean them about once a year and I replace the Pinch rollers after about 10 to 15 years of usage.
Thank you very much for the tip of rerubberin at sofh.it. I didn't know about that. I usually just buy cheap pinch rollers from China, but I have noticed difference in quality so I've saved all the original Pinch rollers from JVC and Panasonic VCR's (see attached image). Next time I will probably try to get these originals rerubbered instead :congrats:

hysteriah, just let us know how this story ends. :)

Well, I can already now tell you how this probably "ends". Unless someone here comes up with a great suggestion to something I can try that might fix this VCR, then I will probably put it away and just save it as "for spare parts" until some of my other JVC VCR's might need some spares ;-)

What's the model of the machine on the bottom of the stack? JVC made a variety of machines with that form factor and color, though were usually higher end machines like DVHS or WVHS. The WVHS ones at least tend to require a lot of work before they're usable in my experience, so good luck with that if it isn't already working.

At the bottom of the stack is the JVC HM-DR10000 DVHS. That one is actually working perfectly... so far :)

So, you don't like the idea of tilting the pinch roller block...
:)

I'm not quite sure what you mean with "the pinch roller block"? ...but I've tried replacing the whole pinch roller assembly (see attached photo) from a VCR that I know for sure works perfectly... so I don't really believe that it has something to do with the pinch roller any longer :hmm:

You mount your assembly on an axle. The idea is to bend it a little bit (almost towards the front) to change the angle of the pinch roller relative to the capstan shaft, to make them coaxial again.

It's hardly as accurate as needed but does the headface look as if it's about 90 deg to the chassis? Can you eye it off to compared it to the capstan shaft or a tape guide? A small mirror can help.

Is there any colored screw sealant on any of the three head screws and the head plate? Sometimes we can tell from the sealant whether a screw has been tampered with. For example it's possible the front screws on the head are set correctly but the back one has been loosened.

I often mark with a fine felt tipped pen the position of a screw or guide before carefully adjusting it. If possible video turning the screw to record the exact number of turns you turned the screw and can return it to that exact original position if needed.

Find the back screw position which stops the tape chewing.

There are no shortcuts. The aim is to fix one problem at a time, the first being to fix tape chewing/damage. If at this point the screw adjustment fixes the tape chewing, be happy, even if audio or picture gets worse. We deal with that in another step.

It wouldn't be wise to adjust something if you're not 100% sure that the specific part is at fault. Until the capstan tape runs smoothly, the problem starts after that. Of course, changing the trajectory before the capstan also changes after. But I wouldn't advice such an ax and crowbar (try and error) adjustment method, it is pointless.

Axe and crowbar?

I suggested he first check, as best he can without special tools, the head face's perpendicularity with the chassis. Also inspect the sealant on each of the three screws for possible clues of tampering from original. He can report back on those things.

It's not a part, it's an adjustment. Remember the adjustment can be completely reversed if he does it right. He can undo it. Also remember his video showed changing A/C head tilt temporarily stopped the tape mistracking and subsequent damage at the capstan and PR.

Changing the tilt may not be the solution or the full solution but it's worth a try because again it's completely reversible. There is no penalty. But if it helps that doesnt finish adjustment of the A/C head. It's just a first step. Assuming everything else seems OK there's still head height to check and if necessary adjust. Then linear audio Azimuth.

But if he doesnt want to go through with this that's his call.

He can do nothing without special tools. If you look video there are clearly visible problem is after capstan. No one should mess with factory settings if they are not clearly out of alignment because someone messed with them before. How to check and repair mechanics is clearly described in SM. If you have not all necessary tools never even start to mess with it. You can replace whole mechanics from cheaper VCR and take only head drum from this.

The machine is useless while it chews tapes.

Head zenith does not have to be exact for a good picture and sound. It's more a long term issue which if incorrect leads over time to keystoning of the head face. I assume you know that from audio tape machine heads? It can also create poor audio pickup or poor control track pickup - but not both at the same time. For testing purposes, obviously we are not concerned with long term keystoning.

And I dont believe at all that he is an expert. That's why my suggestions are very limited and finely focussed so that hopefully he doesnt make things worse.

But of course! Did I say NO? If it skew tape, check mechanics (if you have all tools) and repair, or find working mechanics and replace. That simple. But never mess with factory settings without all necessary alignment tools. That simple. What you offer is vice versa.

Even when the original setting- whether factory setting or not - can be perfectly returned to?

Exactly. Because they can not be perfectly returned no matter what lines you draw with a marker pen and even no point to do it. That's the Papuan method - change something and see what happens.

OK, "Perfectly" was not the right word. Thanks for picking it up. There's always some error. There was a great scientific and engineering advance made when plus and minus tolerances started to be used in specifications and measurements, which implies perfect precision and performance is unattainable with real world equipment.

If we have to return a screw to exactly the same angle we deviated from without even a miniscule margin for error, we could never adequately service a tape machine. For there can be many such adjustments. You dont seem to understand a fumdamental necessity in the real world, the need to make tradeoffs. Who is the unrealistic perfectionist here?

Yes I am a perfectionist but why unrealistic? I do only what I know, can and for what I have necessary tools. No tools - do not start. That simple. For audio I have nearly all (except few Nakamichi head alignment tools rarer than hens teeth, but I have alternative). For VCR I have some of necessary tools, at least test cassetes, video head testers etc., but not all and I can not align mechanics perfectly. So I simply replace it if something is wrong. Keep head drum and replace mechanics. It works. But never mess with mechanics if you do not know what you are doing.

I'm the same. I dont have every tool and the tools I have have their own limitations. I try to use them knowing those limitations. There's an old saying: "do not make the perfect the enemy of the good"

Inversely, don't be lazy/sloppy, and utter the BS phrase "good enough", which is a euphemism for "crap".

There is a middle ground between lazy/junk and unrealistic/utopia/"perfect".

Find that middle ground.

The middle is also not binary, but exists in a range. Better/worse/mid.

As an example:
- thrift story VCR = crap
- better-quality Sony/Sharp VHS models = middle-worse (combined with ES10/15 type)
- non-TBC JVC S-VHS = middle-mid (combined with ES10/15 type)
- with-TBC JVC/Panasonic = middle-better
- VCR that tracking everything always, sharp like HD, etc = unrealistic

When it comes to VCRs, that range between middle-worse and middle-better is still quite wide. But it's simply not broken junk, nor imaginary decks.

All tools have strengths and weakness.
- The best tools have many strengths, few weaknesses.
- The worst tools have many weaknesses, and sometimes zero strengths.

Solved!
 

Okey, here's a small update from the thread starter. I actually think I've managed to "SOLVE" this issue now :eek:

After replacing both the "Pinch roller arm Assembly" AND the "Guide arm Assembly" (see attached image) from another perfectly working VCR, the VCR now seems to be playing perfectly fine! There has been no more eating of tapes after I replaced both these parts earlier today, and both video and sound quality is exactly as it should be (I've compared it with a perfectly working JVC HR-S7700 and they seems to be equal) :congrats:
I almost can't believe it myself :huh1:

It might looks like I made a "mistake" when I changed the pinch roller, simply by "tightening" it a littlebit too tight to the axl. After loosening it a little bit, it now plays fine also with the original "Pinch roller arm Assembly", but the "Guide arm Assembly" must be replaced. Thankfully I do have other VCR's I can "borrow" it from :)

I haven't had this VCR for a very long time and I don't know anything about it's past. But there's really no signs of heavy usage and wear inside of it, but it looks like it might have been handled roughly, with several nicks and marks on the outside. It was also not packaged very well when I received it in the mail a while ago. That might explain why the "Guide arm Assembly" must be replaced? :question:

Thank you so incedibly much to each and every one of you who has participated in this thread! I could never have done it without your help :congrats: :congrats: :congrats: