JVC M71

[Macs]

Yes yes y’all, im new to this site so hello and thanks for any help you can send my way.
I just got the JVC M71 and it worked fine with batteries the first day. It was super dirty but complete well cared for. Basically sitting on a shelf in the garage for decades, in S. Florida.
The tape played but dragged a bit. The sliders were scratchy but you could set them to a spot that worked ok.
So sprayed some deoxit to try ti improve things and everything went to hell.
The tape deck went bananas.
It wont stop, Also when I tried a power cord there is a humming from inside the box ( not the speakers).
anyway, any advice would be helpful. I don’t know what I’m doing obviously and don’t want to do any further damage.
Is there anybody out there that works on these for pay.
I looked through this forum the last few days but couldn’t find one. Everyone seems to be working on their own.

 

[Tinman]

Right off the bat, I'm sure it needs new belts.
The humming could be the transformer.
Is it a quiet hum or really loud?
I have no idea why the player won't stop.
I've had and sold both an M70 and M71 but it's been years so it's tough trying to remember the inner workings of them.
Be careful with these sliders.
Because they're on the top, there can be all kinds of dust, dirt, hair, bugs, etc. in them.

 

[Macs]

Hey, thank you very much. Id say it’s a pretty loud hum. I’ll look into getting the belts ordered. I haven’t decided if I’ll try to do any work myself yet.

 

[floyd]

That hum usually happens when the caps on the power board are dried out or close to going out . I have the same problem on several boomboxes but I hate working on them because my boxes are overly complicated and there's no easy way to approach it lol.

 

[Superduper]

The hum could just be from the cassette motor running. You normally don't hear it because when the deck plays, the audio is typically louder than the motor noise. I would say that the belts basically were ready to go and by running the deck, they snapped and so now won't shut off until the deck is reset. Deoxit is a solvent and it's supposed to be used very sparingly locally. If you sprayed it all over the place (remember, it's a liquid solvent and will drip). I would say that the unit probably needs a general service. That includes deck service, cleaning of all switches and sliders. Most RC-M70/71 types with sliders may also have issues with those controls too internally. That could involve necessitating rebuild of that slider control board.

Anyways, there isn't a single failure point that you can point to simply from a symptom, there could be many causes.

 

[Macs]

Thanks everybody ! I’ll continue my research. If you all know of anyone near south Florida who does this work please have them reach out.
here’s a picture of my other box. It’s aGeneral Electric. It has a weak left channel. I’ll start a post on that one some other time. Thanks again, Max

 

[Tinman]

I own two of the GEs, they're awesome boxes and fairly hard to come by.
Here are two threads of mine from last year about them.
Link1, Link 2
Link 2 may actually be the problem with yours.

If I remember correctly, the M70 isn't that difficult to work on.
If you decide to undertake the repairs just remember to take a lot of pictures (and from different angles) as you disassemble it.
The M70 & M71s are pretty common, just go to forum, tech talk, JVC, M70 and you should find gobs of info on them.

 

[Macs]

Tinman, thank you very much for this info.

 

[Macs]

I own two of the GEs, they're awesome boxes and fairly hard to come by.
Here are two threads of mine from last year about them.
Link1, Link 2
Link 2 may actually be the problem with yours.

If I remember correctly, the M70 isn't that difficult to work on.
If you decide to undertake the repairs just remember to take a lot of pictures (and from different angles) as you disassemble it.
The M70 & M71s are pretty common, just go to forum, tech talk, JVC, M70 and you should find gobs of info on them.

Would you happen to know the belt codes for the GE 5268 ?
I’ll probably work on mine next.

 

[Tinman]

I'll see if I have them written down.