EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: abhi1981 on December 16, 2022, 07:03:40 pm
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Hello everybody,
Just got a cheap Panasonic VCR NV-FJ730 ""Hi Fi stereo"". It was powering up, but the would not accept the cassette.
The mode switch was broken. I used baking soda and super glue to fill up the broken area, and then fixed an earbud stem as the spindle.
Now, the VCR is working normally, there is picture and sound from both channels, but after playing for about 20-30 sec, the take up spool stops and the reel starts bunching up near the capstan. I tried another cassette, but the same thing happened.
Rewind and fast-forward works really fast, but sometimes that also struggles.
Please help.
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Service manual: https://www.download-service-manuals.com/download.php?filename=Panasonic--Z-Mechanism--service--ID2172.pdf (https://www.download-service-manuals.com/download.php?filename=Panasonic--Z-Mechanism--service--ID2172.pdf)
More info: https://www.reptips.dk/Reptips/PAN-Z-MECH.pdf (https://www.reptips.dk/Reptips/PAN-Z-MECH.pdf)
Check the belt and idler mechanism.
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Those are so old the belts will be stretched and brittle. Replace all the belts first.
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Service manual: https://www.download-service-manuals.com/download.php?filename=Panasonic--Z-Mechanism--service--ID2172.pdf (https://www.download-service-manuals.com/download.php?filename=Panasonic--Z-Mechanism--service--ID2172.pdf)
More info: https://www.reptips.dk/Reptips/PAN-Z-MECH.pdf (https://www.reptips.dk/Reptips/PAN-Z-MECH.pdf)
Check the belt and idler mechanism.
Thanks for providing the link. Although it is not Z mechanism, but still the manual contains lots of info.
Can you please identify the mechanism??
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You may need a new pinch roller also with the belts.
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I changed the belt, but it did not help. The original belt is fine too and has good tension. May have been changed in the recent past. New pinch roller will be next to impossible to find in India :( :(
I'll check the clutch and idlers .
The "technician" >:( who had tried to change the mode switch ( shoddy soldering and broken traces), had also changed the onboard tactile switches. I wonder if they are causing some sort of problem.
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You're right, that does not look like a Z at all. The strange thing is, the model-specific manual at https://elektrotanya.com/panasonic_nv-fj730_fj732.pdf/download.html (https://elektrotanya.com/panasonic_nv-fj730_fj732.pdf/download.html) says it's a Z mechanism.
But after a bit more searching, I found that what you may have is an R4 mechanism:
https://www.eserviceinfo.com/downloadsm/100346/panasonic_r4-euro%20mechanism%20198.html (https://www.eserviceinfo.com/downloadsm/100346/panasonic_r4-euro%20mechanism%20198.html)
https://www.eserviceinfo.com/downloadsm/103526/panasonic_panasonic%20r4%20vcr-mechanika.html (https://www.eserviceinfo.com/downloadsm/103526/panasonic_panasonic%20r4%20vcr-mechanika.html)
Are the Z and R4 somehow drop-in replacements, and someone replaced the mechanism in the past...?
In any case, it's a new enough generation that I don't think belts are going to be a problem. There's usually a felt clutch that applies tension to the take-up reel - if the reel stops, check that it's not slipping.
Another thing to note is the automatic head wiper arm is still present, it's usually recommended to remove them and manually clean the heads when necessary, since they can damage the heads: https://www.vintage-radio.net/forum/showthread.php?t=122684 (https://www.vintage-radio.net/forum/showthread.php?t=122684)
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Wow!!! That's exactly what I needed. Thank you very much amyk for your help. :-+ :-+ :-+
Totally agree with you, the first thing I did was remove the automatic wiper. The wiper sponge becomes hard over time and will scratch the head.
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FINALLY!! PROBLEM SOLVED
My fault |O |O |O |O
I forgot to put the spring inside the clutch :-[ :-[
It's working perfectly now.
Many thanks once again to everybody for their kindness and patience.
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Hmm... Make sure you don't have any spare parts left behind on the bench!
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Hmm... Make sure you don't have any spare parts left behind on the bench!
;D ;D ;D ;D
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The volume level has suddenly dropped significantly :o :o. I tried the same cassette on a different VCR and the loudness was much higher :rant: :rant:.
I cleaned all the heads and ribbon cables, but it didn't help.
Is the audio head damaged??
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Check the tape position and tension on the audio head. It may be not touching the head surface enough. Has the head moved by any chance?
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I don't think the head has moved. The tape position is okay, but don't know about tension. I believe a special meter is required to check tension. Visually it seems okay.
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Does that model have Hi-Fi stereo sound? If yes, is the low volume on both the linear track and the Hi-Fi track or only one of those?
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Yes, it has Hi-Fi stereo sound. The volume is only on the linear track because if I pull out the linear head ribbon, the sound stops. Both channels are working.