JVC RC-838 Issues with radio dial and tape deck

[snuci]

Hi All,

I am new here but not new to boomboxes. I do not have a collection but I did have a JVC RC-M70C back in the day as a teen. I did acquire a JVC RC-838 and recently decided to check it out. I mainly used it to amplify an iPhone play list. I had to use detox-it on the Mode switch as it was all messed up and that is fine. Sadly, when I tried to move the tuner dial, the internal string broke so I need to fix that. The cassette moves, rewind, fast forward but it sounds garbled.

First question. Is it common for the radio tuning string to break after all of these years? Is it as easy as re-stringing it or is there a more involved process?

Second question, can the cassette issue be due to needing demagnetization? I cleaned the heads but it's still the same. Truthfully, I only have one remaining cassette from the old days so it may actually be bad. Perhaps I should just get an new cassette tape and record some music and see if it's okay?

Any help is much appreciated.

 

[hopey]

It an old Box and these are notorious for having many internal contact corrosion problems. The tape deck needs new belts and maybe the motor needs replacing.

 

[snuci]

Thank you for the info. Where can I find the correct belts for this model?

 

[BoomboxLover48]

The pinch roller rubber getting hard is one of the causes for the garbled sound. The rubber will bot grab with the capstan axle and pull the tape as it should.
Belts all might need replacement and then do a complete deoxit treatment. Mist of the front are levers that move switch knobs a bit far from behind it. You will find it easy to locate them when you move each front switches.

Re threading or putting a cord needs patience and be careful not to break any axles of the pulleys. One has to pay attention on the turns it makes on the mail tuning knob axle. I used masking tape just to hold it on the pulleys as i run the cord from and to the flywheel. It will be a good idea to to take the broken cord, stretch it and measure the original length and then have a good idea on where to make the knots. A spring of ~ 1 inch or shorter holds it it position to the flywheel side of it. I've done so many of this threading on tube radios and boomboxes. Once you do one it becomes much easier. The last one I did was on Sharp GF777.

You should be able to get a threading diagram showing the turns and all in the schematics. Patience... be patient... you will do it well.
Page 13 of schematics has the diagram.

You can download it from the Library here and look under JVC RC 838

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The first main belt is a flat type FRM 9.6 and the second is a counter square belt small SCY 4.6
9.6 and 4.6 are in inches.
Other members can confirm it.


~Royce

 

[snuci]

Thank you BoobboxLover48. I really appreciate the info and the link to the documentation as well.

 

[Dbzerk]

Hi.. I just started to pull my 838 apart today, what I thought was a broken dial string turned out to be a broken pulley. The one behind the tuner knob.. it actually broke off the mount and the string is still intact.. could be similar problem to yours?