Problem with JVC KD-A22

[Ilikemusic]

Hello. I just bought this cassette deck yesterday. It looks nice but I was in a rush and couldn’t try it before buying it and it was a good deal. It is a JVC KD-A22. Basically after I hit play, ff or rewind the tape stops after like 3 seconds. I don’t have technical experience with anything like this but I am willing to try things. Is it an easy fix in your opinion? Thanks

I added a little video to YouTube showing the issue.

[Enzo]

Does the take-up reel stop turning before it stops? Most old tape decks suffer from aged rubber. A little mineral spirits will rejuvenate a lot of them. I suspect your deck is not able to turn the pickup reel well. If not a belt then an idler wheel.

[oc disorder]

Just when we thought it was safe to come out of the workshop someone arrives with a cassette deck !!
Seems like it was a good one in its day with published specs like "Frequency Response: 30Hz to 16kHz (Metal tape)" !

Step 1. what Enzo says.

This deck has a little magnet that rotates (from what I can tell) near a miniature reed switch which opens and shuts as the magnet passes by it.
This tells the mechanism NOT to auto stop as the tape is playing , fast forwarding or rewinding .
This is mounted on the tape counter which is driven by a thin belt .
From your smaller than Ben Hur movie we can't catch a glance to see if the counter is counting or stationary.
So with a bit of luck and a fair breeze it may be this belt.
The counter may have jammed or there may be some other mechanical reason (eg lack of lubrication) why the take up pulley and thus the counter is not turning.
There are two belts from what I can see in your deck.
One from the motor and the counter belt.
It seems the motor one is not available as a spare part from here but the counter one is.
If there is a broken belt lying in the bottom of the deck don't throw it out just yet until you measure it.
It may be possible to buy a third party belt !
There are places that explain how to measure a belt.
Good luck !

VKB3001-007 - MOTOR BELT-------------------N/A
VKB3000-012 - COUNTER BELT -------------5.95 USD

https://encompass.com/model/JVCKDA22J

[Ilikemusic]

Thank you Enzo and oc disorder for your answers and taking the time. Please consider I have no experience with any of this but this is kind of real life challenges that made me want to learn and have fun in the process. So, I was looking at the mineral spirits recommendation, a substance I have never heard of, and in the process google recommended something called "Rubber Renue", is that something that would be more specific or should I stick with the mineral spirits, I don't have either and I don't know if you were recommending the mineral spirits because most people would have some at home, again I know nothing about this sorry.... oc disorder, I thought I got pretty close with the video and it is in 4K, but maybe I am not pointing at the right thing. How could I make it better to show what is failing? Thanks for taking the time to watch the video btw. Also, I have no clue as to where or in what measure I should be applying the mineral spirits, I did some research after the recommendations but it only made me realize that I have to educate myself more on it. I found some pages of a service manual but I still couldn't figure out where the rubber parts to use the liquid are. I am including them here. Thanks in advance!

The manual

https://www.manualscenter.com/manual...l#.Ym9aPJPMJhE

[Enzo]

I used to work on this stuff daily, and we used to use tape in the music biz. But you have one unit to fuss with, so if you want to buy a commercial product, go ahead. I can't afford to pay those prices. A pint or quart of mineral spirits from the hardware/paint store will last me quite a while. and costs darn little. Rubber Renue or other similar are not cosmic, I used to work in the coin industry, we had pinball machins amongst other stuff. Every pinball has tons of white rubber rings on the playfield. They go dead or harden, and we used mineral spirits on them to rejuve them. Actually even gasoline will work, but it is far too dangerous to use.

I use plain old Qtips. Dip an end into the sauce, shake off the drip, and wipe my rubbers.

[Ilikemusic]

Thank you Enzo, I only asked in case you liked that rubber renue thing better, it was $18 and the mineral spirits is $10, I don't think I will be needing that in the future enough to pay the $30+ for the big bottle. So, since I couldn't see the belts you were talking about I had the magnificent idea of open the whole thing to find the belts in question. I recorded another video so that you guys can take a look. I tried to jam the mechanism that snaps and stops the tape and so it records fine, I was willing to not have auto stop function, but on playback I am able to hear the thing trying to stop the tape every two seconds. Thanks for your patience.



https://youtu.be/YdHjC-sm9x0

[Jon Snell]

The take up spool tells the mechanism to stop the motor if it stops turning. The takeup spool has a magnet on it and as it rotates activates the reed relay, that produces pulses and the motor carries on turning. When the pulses stop or when play is first pactivated, there is a 2 Second delay. This allows the take up spool time to rotate or not.
Check the take up spool drive and replace the counter belt.

Here is the service manual to enable repairs without breaking the mechanism; https://www.hifiengine.com/manual_li...c/kd-a22.shtml

[oc disorder]

Well that video shows the magnet rotating on the back of that pulley.
I'm a bit perplexed by the music scan function which detects no signal on the tape before a recording.


What happens when you put a tape in , press pause and then play ?
If it just sits there waiting for you to release the pause button read on !

The pause button as well as mechanically stopping the tape moving also disables the
"auto stop brain function" i.e. the electronics that detects if the wheels are going round.
When in pause as the wheels are not turning the magnet stops pulling the reed switch open and shut
but the auto stop solenoid that pulls the whole mechanism out of gear does not operate as a little switch
on the back of the mechanism tells the auto stop brain function "we're just in pause mate,
don't disengage the whole show " !

My theory is .... with a tape in the machine in play & pause and the auto stop function doesn't operate
I.e. the mechanism doesn't disengage so the door wont open , it is possible to disable the auto stop function
by shorting the two terminals on the pause internal switch which would show the auto stop circuit is faulty.
According to the manual the wires are orange and grey and they lead back to terminals 5 and 15 on the main
circuit board VMW 1536 A (top right hand area). This also disengages the music scan function.

You probably need to phone a friend with a soldering iron and some basic knowledge of electronics.


The whole service manual is available here free but you will have to register
https://www.hifiengine.com/manual_li...c/kd-a22.shtml

"However, registration is required to access members only resources such as downloads, posting requests, reviews and sharing images.
Registration is free of charge and your activation email should arrive within a few minutes (depending on your email provider)."

[Jon Snell]

Why are you over thinking a simple problem?
Theory is not required, the practicalities are explained in the service manual. It is only a tape recorder with a deck issue after all.

[oc disorder]

"Why are you over thinking a simple problem?" Well apart from not much else to do in the second video the pulley that drives the counter appears to be rotating evenly which suggests to me that the belt from the take up spool and therefore the takeup spool itself are not the issue. Also attempting to provide additional information for informed gentlemen such as yourself who may not have access to that information.
On occasion it does occur to me a concise answer e.g." fools rush in where angles fear to tread" may apply to some hasty purchases but I like to where possible give some encouragement to people who restore equipment that would otherwise end up as landfill . If my advice is inaccurate I would appreciate being corrected , this forum is usually a place that encourages learning of a practical nature.

[Jon Snell]

As a service engineer, I always check the obvious first before trying to figure out how a system works.
If the spool is rotating, have you got pulses feeding the positive side of C13?
Have you checked R4 a very common issue back when I was an Authorised JVC Repair Agent, before I retired. There was a mod to the resistor, use an MF type 2W if my memory serves me correctly.

[Ilikemusic]

So what I really would like to do is to destroy the auto stop mechanism. I don't mind just operating this manually and I am the only person who is going to be using. Jon, thank you for your time but I am a complete ignorant when it comes to this, all that I have ever done is replace components in a BOSS DS-1 so if I could avoid messing with the electronics I would prefer that. Now if you tell me that I will not die electrocuted I might consider messing with the electronics. OC Disorder, I cut the orange and grey wires you were talking about, I made the assumption that is what you meant by "shorting" but it made no difference at all. Also, the behavior with the cassette is the same as with no cassette, it stops after 2 seconds no matter what I am doing. You guys were talking about a magnet, could I remove/destroy/jam any components to that I don't get that pulse from the autostop? Thank you for your patience guys.

[Enzo]

The magnet doesn't trigger the stop. The stop circuit has a timing function. The magnet keeps resetting that timing so it never times out.

The autostop works when you get to the end of a tape, it stops rather than keep on tugging at the tape.

[Ilikemusic]

Thank you Enzo, I removed a spring and so that has render it useless, it does not stop, but I can still hear the pulse. Is there a way to get rid of it?

[oc disorder]

Shorting = short circuit = joining together . The opposite is open circuit not connected which is definitely what you have now.
Strip a little bit of the insulation (plastic) from those wires and twist them together making sure they don't touch the chassis perhaps cover in sticky tape just to make sure.
Now it won't try to auto stop as it thinks it's in pause ie it thinks the switch at the back is closed.
It would help if you answered Enzo's first question before we dived in the deep end. "Does the take-up reel stop turning before it stops?" although from the second video
it appeared the counter pulley was still turning while the mechanism was trying to stop.