No audio on tapes with JVC HR-S9600-MS?

[qcalv]

Hello,

I just acquired the SVHS deck JVC HR S9600 MS. It can read SECAM (France) format and convert it to PAL. I used in the past other VHS decks reading SECAM. I have commercial tape and private tapes in SECAM as well.

Now I am really happy about the quality results compared to the previous VCR decks, BUT I do not get any sound when playing the private tapes (and that's why I acquire it...).

1. Commercial tape works fine (audio configuration of deck: NORM or HIFI) on the JVC HR S9600.
2. Private tape works fine in other VCR deck (VHS only). Sound and video comes out.
3. But for these private tapes on the JVC HR S9600 I could not get any configuration (NORM, HIFI, and others) where I get sound out of the SCART output or even RCA outputs. Video works great.

I don't get it. As soon as I turn PLAY, I cannot change the AUDIO configuration, it sets automatically to "NORM" but anyway no audio at all. I do not see even any volume variation on the front screen of the deck.

What am I missing? I cannot believe this deck is not able to read my private SECAM VHS whereas cheap decks are.

Any help would be really appreciated!!

Thanks.

Fran

[latreche34]

Does it play normal sound from other tapes? Most likely there is something wrong with the linear audio section you need to have it checked by a technician where you live or sell it an move on.

[qcalv]

What do you mean by "other tapes"?
As I wrote commercial tape: yes.
My old personal tapes: no.
I tried today a "younger" personal tape, and sound was playing. However, only if I set following audio mode:
HIFI Left and HIFI+NORM (which is a mix between HIFI and NORM). When I put only NORM: no sound. When I put only HIFI Right: no sound.
What can be wrong with the linear audio section? You mean the head? Are the heads combined between HIFI and Linear?
In the service manual for the A/C head, I see following pins:
PEC, PEB, GND, AUDIO ERASE, GND, CTL+, CTL-. I know the tracking is working properly as I tested and it dealigns the video.
Regarding service technician, I leave in germany, but this VCR is specialized for France (MS > SECAM), so I am really not sure if I want to give this here somewhere, especially in 2022...

[latreche34]

Well it's obvious that the linear audio is not working, What's the cause? I don't know, I don't have the VCR in front of me. It requires some technical skills and tools to repair these things that's why they had technicians back in the day.

[dpalomaki]

If "private" r tapes are the only problem we need to know more about them
Are the "private" tapes:
- original VCR recordings
- camcorder recordings
- copies from a recording

I've encountered loss of audio (in left, right, or linear track) resulting from failed solder joints and broken circuit board traces. But that would not account for some tapes playing linear ok and not others.

I've also encountered apparent loss of linear track audio while HiFi audio remained resulting from phase cancellation of left and right channels being mixed to form the mono linear track. (This often happens when a balanced mono source is connected to the left and right channel inputs using simple splitter cable.)

VCRs will often automatically switch to "norm" if they do not detect a Hi-Fi track.

A workaround is to record the audio from a VCR that works for the problem tape then combine it with the video. You might need to insert/delete audio samples if the video and audio recordings drift.

[RobustReviews]

Yeah, this is a puzzler.

To clarify the HiFi sound system and the linear sound system are fundamentally different, the heads aren't shared. I've had some issues before with the rare stereo-linear machines and mistracking audio but that's unlikely here from the symptoms you describe.

There is something awry here, the HiFi left and right are modulated on to separate carriers on the VHS system, it follows that to complete lose one channel would indicate an FM discrimination fault - that's going to need further investigation. If the machine is tracking one channel it's unlikely it won't be able to track the other as they're both recorded to the same portion of tape and they're very close in frequency.

A head clog is not 'impossible', but it's unlikely, especially if the L-HiFi channel is strong and noise-free.

I'll see if I can find a schematic and see if there's a component that might tie loss of R-HiFi and linear sound together, it's a curious fault and providing there's no obvious explanation it's going to be a headscratcher.

-- merged --

Right after a quick look over the schematic, it's going to be an ache if it's nothing obvious, which we've still not discounted.

To clarify, you do:
Get a mixture of linear and HiFi in 'mix' mode.

You do not get any audio in:
HiFi Right
Linear/Normal only?

[qcalv]

Hi RobustReviews,

thanks for answering. Sorry, I did not check lately. Actually, I brought the deck to a technician here in germany, and he was supposed to repare it. He told me he found a flat cable having some connection issue and he replaced it. Well, today few months after, I managed to test it. And I still get no audio. I am going to bring it back in few weeks. Hard to find people still being able to repare such things correctly.

To answer few questions:
- The private tapes are either camcorder direct recordings or copies from recordings (but all originally from a cam corder bought around 1987)
- The "older" tapes (means recorded in 1989+) play sound correctly on my Samsung SV-125FK so I know the audio is fine on the tapes
- I have got "newer" tapes (means recorded out of DV camcorder in 2005+).

When I play the "older" tapes in the JVC deck, I got no audio. That's my issue. I cannot control the audio using the button on front of the deck, it just says NORM.
When I play the "newer" tapes in the JVC deck, I get audio in these situations (I switch between them by pressing the "Control audio" button):
1. NORM only > No audio
2. HIFI+NORM > I get audio but you hear that audio is less intense
3. HIFI Left+Right > I get audio
4. HIFI Left > I get audio
5. HIFI Right > I get audio
So to summarize I do not get audio at all when I go in NORM only mode with "newer" tapes (in manual it just says it is for "tapes with dubbed audio").
And with "older" tapes I do not get audio at all.

And to make it more complicated, I got one "newer" tape (as well originally from DV camcorder) where it plays only when I put in Left audio. Right audio gets no sound. But that's probably an exception...

Thanks for following up.

[latreche34]

As I said in post #4 you have a problem with linear audio (Normal), Just take it back to the technician with one of the tapes you have problem with. If you want help here you are going to have to post some audio samples, A lot of people consider weak audio as no audio but it is just way lower than the HiFi one, Also a noise pattern can pinpoint what the problem might be.

[dpalomaki]

^+1. When audio is in HiFi+NORM mode the system mixes the normal and HiFi audio something like 50/50. With no NORM audio making it to the output section the level will be cut in about half - you hear just the HiFi sound.

Many camcorders would only record NORM (linear track) audio, so those tapes will put any audio on the HiFi tracks. The system will not allow you to select HiFi output if there is no HiFi signal on the tape. (The machine can detect whether or not a HiFi signal was recorded thanks to the FM carriers the spinning head reads, but it generally cannot detect the difference between no recorded linear track and a silent linear track.)

Finding the issue starts with tracking the linear track audio signal through the system to determine where it stops. It could be as simple as a bad connection at the head.