What's happening with my JVC HR-S9500?

[hysteriah]

Something happened with my VCR tonight. The counter stops counting (like it does on erased tape) and the auto-tracking system gets activated. I've tried cleaning the whole thing but it doesn't help. What's causing this? Bad videoheads?
Any suggestions on what to do? Please help
Here's a video that shows the problem:
https://youtu.be/yxCn1e8oodg

[Tester]

Take a look at the tape itself.
That behaviour is fairly typical of latter JVC players when the tape edges are damaged (even slightly). In fact, these machines have a tendency to do that damage themselves (with normal playback) when the tape transport goes slightly out of alignment. It's been covered on the forums —the gravity is apparently to blame.

So your unit might not be "dying", but would most likely need a touch-up.

[hysteriah]

Thanks for your reply, Tester :-)
But no, it doesn't seems like it has to do with the tape. The tape edges seems perfectly fine and the tape plays perfect in my other JVC's (I've tried both the HR-S7600 and the HR-S7700).

I discovered something new today. After dealing with this error yesterday, I simply unpluged the VCR from the wall socket and let it be unpluged over night. When I pluged it back in today, it plays the same tape perfectly fine today. It must be some kind of electronic circuits components failing, but starts working again after being unplugged for some time... until it just dies for good I'm afraid. But what can it be? Maybe a capacitor?

[Quasipal]

I had this exact problem caused by a failing capacitor - albeit in a Panasonic D80. Simply, the sync pulses were not getting through and so also the tracking 'drifted' as the VCR needs sync pulses for this. Also sound was muted as machine thought it was a blank tape...

Not saying yours is caused by this, but I have had a capacitor cause this problem. Make sure the ACE is super clean also - look at it through a loupe as tape binder can build up on it by the dragging.

[hysteriah]

Sound VERY similar to my issue, Quasipal. On mine, when this happens, audio also fades out. It doesn't get completley muted, but very faded :-( Damnit, this was the last one of my really Hi-Q VCR's that was working 100% properly :-( Where to get a "new" one in Europe in 100% decent shape, preferably refurbished? Anyone who knows?

[Quasipal]

Quote:

Originally Posted by hysteriah

Sound VERY similar to my issue, Quasipal. On mine, when this happens, audio also fades out. It doesn't get completley muted, but very faded :-( Damnit, this was the last one of my really Hi-Q VCR's that was working 100% properly :-( Where to get a "new" one in Europe in 100% decent shape, preferably refurbished? Anyone who knows?

Well as it seems to be a fairly simple fault why don't you get it repaired? If it works well apart from that issue then you know you have a good machine, just needs a quick fix. Worth a try!

We have the service manual on Digital FAQ I see, so that is a start right there.

I will be selling a JVC 8700 SVHS in new condition fairly soon, but if you already have a nice machine it would be a shame to scrap it for one fault. Do you have any local technicians who maybe can help you.

[hysteriah]

You're right... but it's hard to find technicians around here who still remembers how to fix VHS machines But I'll try my best to see if I can find one ;-) Once again thanks a lot, quasipal. You've been extremely helpful!

[Quasipal]

Quote:

Originally Posted by hysteriah

You're right... but it's hard to find technicians around here who still remembers how to fix VHS machines But I'll try my best to see if I can find one ;-) Once again thanks a lot, quasipal. You've been extremely helpful!

No problem - just a shame we don't live a bit closer or I would look at it myself. At this point in time all VCR's are in need of a tuneup so yours will likely perfom better after a service than it did beforehand. I'm even having to repair even low use machines as grease has dried out or migrated.

[hysteriah]

Quote:

Originally Posted by Quasipal

No problem - just a shame we don't live a bit closer or I would look at it myself. At this point in time all VCR's are in need of a tuneup so yours will likely perfom better after a service than it did beforehand. I'm even having to repair even low use machines as grease has dried out or migrated.

Yes, you are perfectly right. I got my hands on this Panasonic NV-FS200 with very little usage... acording to the seller it was only used for playback of less than 20 tapes in total when I got it... and I belive him, because the unit really looks like brand new inside without any signt usage at all. But even in such good condition, my unit has some very anoying issues that makes it not suitable for digitizing my tapes. Every now and then, a black line apears all over the screen... and on playback of SVHS tapes, the colors are really odd. This tells me that there's something terribly wrong and I don't want to use it until I've got it fixed properly. I don't want to destroy it more than it already is. I know these units has a reputation of having capacitors going bad over time, so I guess that might be a part of the reasons for my problems?

What's your thought on these problems, QuasiPal?
And yes, I really need to find a a skilled VCR engineer who can help me out with some of my VCR's here in this part of the world

This is how the colors looks when playback of SVHS tapes


This is the Black Stripe that's appearing all over the screen from time to time (this happens only when the TBC is activated)


This is how my NV-FS200 looks inside, in my opinion it looks like brand new... but that didn't help much

[Quasipal]

I think what you have there is a failing module on the Chroma board. I had a machine with very similar symptoms here http://www.digitalfaq.com/forum/vcr-...nt-issues.html and to be honest, this is starting to be a worry. I have seen decks for sale on eBay and elsewhere all with similar issues and apart from this and PSU capacitors, the FS200 is trouble free.

I was not able to fix this by obtaining parts as they are NLA. Only suggestion is to find a rough and maybe mechanically broken FS200 to take the board from. Its machines that spend years out of service that fail this way so regular light use may prevent this happening. The board has the delay line on it - pull out board with one connector.

[hysteriah]

Quote:

Originally Posted by Quasipal

I think what you have there is a failing module on the Chroma board. I had a machine with very similar symptoms here http://www.digitalfaq.com/forum/vcr-...nt-issues.html and to be honest, this is starting to be a worry. I have seen decks for sale on eBay and elsewhere all with similar issues and apart from this and PSU capacitors, the FS200 is trouble free.

I was not able to fix this by obtaining parts as they are NLA. Only suggestion is to find a rough and maybe mechanically broken FS200 to take the board from. Its machines that spend years out of service that fail this way so regular light use may prevent this happening. The board has the delay line on it - pull out board with one connector.

The stange thing is that the colors are perfectly fine on playback of regular VHS tapes. It's only the SVHS tapes that makes the colors so strange. The black line over screen is present on both VHS and SVHS tapes, but only when the TBC is enabled. If I switch the TBC off, then the black line never apears.

Does both errors come from the same issue from this Chroma Board, or is it two different errors?

Here's how the colors look on a regular VHS tape:

[jwillis84]

I have read here and elsewhere that DNR and TBC can be a problem with SVHS sometimes, and your better off switching them off (if possible) and using an external TBC (if available). Not all VHS recorders will offer the ability to switch off the DNR/TBC, but those that do.. often are sought after and prized and priced (higher) on eBay by the people that know they have the ability to turn TBC off.

The buyers guide (I don't think) currently indicates which will not allow you to switch the DNR/TBC off.. but I think that's because its not often advertised as a feature.. and people usually assume (more is better)... experience.. like your getting.. can teach you however that under certain circumstances less is better.

As for (why) it happens.. I think.. its because the DNR/TBC in the less than Full Frame TBCs has too little memory to compensate for jitter that stretches beyond its limited buffer of a few lines.. the result is a regenerated signal that "assumes" a missed blanking or missed color burst signal and throws one in for good measure.. which is why the bar looks near perfect.

The Lesson to learn is (whatever works.. run with it.. and don't worry too much about understanding).

Memory chips used to be very very expensive.. digitizing and including a digital memory chip inside a VHS recorder was very expensive for the time and raised the price of the prosumer and professional decks that could perform DNR/TBC.

External TBC units themselves were astronomical in price and for that usually had enough memory to convert and hold an entire two fields of lines and reconstruct a Full Frame of video. Its a tiny amount of memory today, but the old external TBC units still hold on to their value because they aren't making them anymore.. they are a speciality item.. and very sensitive to long play time and heat.. the memory chips start getting flaky if run too long without adequate cooling.. and big boxes and fans.. added more cost to the units.. so they left that up to the broadcast control rooms to provide.. the editing bays had their own in cabinet augmented cooling systems.

Today a typical user puts the rack mount or tiny plastic or metal box on top of a hot VCR and runs them for 8 hours or more.. or puts a tiny fan direct on the TBC introducing spurious RF from the fan magnetic motor directly on top of the input or output lines.. squigglies.. blackouts.. all sorts of flaky behavior. .. Plan accordingly.

To my way of thinking.. heat pipes, modern desktop computer liquid cooled radiators with the fans far away.. or simply huge finned Gaming PC heatsinks would be a lot more practical.. than an editing bay in your garage with its own chilled water air conditioning system. Short cables also help.. using long aerial antenna wire for video cable is not.. fully thought out.

[Quasipal]

Quote:

Originally Posted by hysteriah

The stange thing is that the colors are perfectly fine on playback of regular VHS tapes. It's only the SVHS tapes that makes the colors so strange. The black line over screen is present on both VHS and SVHS tapes, but only when the TBC is enabled. If I switch the TBC off, then the black line never apears.

Does both errors come from the same issue from this Chroma Board, or is it two different errors?

Here's how the colors look on a regular VHS tape:

I have only had two decks with this trouble - both caused with problems on the Chroma board. The fact that what you have looks similar may mean nothing - or everything! Just impossible to exactly say from afar.

I have here a faulty FS200 chroma board and I am determined to find out exactly which component is causing the trouble so may be a fix for machines in the future. I narrowed it down to one section but I want to narrow down further if I can. I'll do this when I have time and share my findings.

[hysteriah]

Quote:

Originally Posted by Quasipal

I have only had two decks with this trouble - both caused with problems on the Chroma board. The fact that what you have looks similar may mean nothing - or everything! Just impossible to exactly say from afar.

I have here a faulty FS200 chroma board and I am determined to find out exactly which component is causing the trouble so may be a fix for machines in the future. I narrowed it down to one section but I want to narrow down further if I can. I'll do this when I have time and share my findings.

That would be great, Quasipal. Please keep in touch with what you discover ;-)

[deter]

Kind of interesting problems. Have a few of the these JVC decks for sale on this site, 9911 and a 9600, I know they are working perfect. These machines don't have that many caps, they are not like the Panasonic decks were you need to rebuild everything.

The biggest issue I found is in the loading and the way the tape sits. The next issue is this plastic part which sits under the video head. This causes the machines to short. This part is made very cheap and they are in the 9000 series. To be honest the part is pretty much worthless as far as what it does.

Repaired a 9900 earlier this year and it was my own, that stupid plastic part was like $250 and than I had to remove the video head and place that part back in.

If it is not broken, you can go in and try to play around with it ad in wd-40 or whatever, sometimes it will fix it. It is not that hard, one of the members from the site called me on the phone, explained this, and we fixed it over the phone.

PM my account, and call me, will try to fix this over the phone.


My guess you may have one of those problems. It is hard just watching a video.


Honestly this year trashed about 3 or 4 of these decks cause when the electronics goes it is just easier getting a new machine. From the video I didn't see the normal signs of electronics failure.

[lordsmurf]

Quote:

Originally Posted by jwillis84

I have read here and elsewhere that DNR and TBC can be a problem with SVHS sometimes, and your better off switching them off (if possible) and using an external TBC (if available).

No, that's not it. Internal TBC cleans image, external cleans signal. Turning off TBC rarely suggested. DNR is part of TBC module, and reason it exist in unit.

Quote:

Not all VHS recorders will offer the ability to switch off the DNR/TBC, but those that do.. often are sought after and prized and priced (higher) on eBay by the people that know they have the ability to turn TBC off.

Panasonic decks can partially turn off DNR, but effects are not helpful.

Quote:

As for (why) it happens.. I think.. its because the DNR/TBC in the less than Full Frame TBCs has too little memory to compensate for jitter that stretches beyond its limited buffer of a few lines..

Yes and no. You also have line vs. field to consider.

Quote:

Memory chips used to be very very expensive..

Still is. Seen those prices lately? 300%+ over 2016 in 2017