RC-550 Motor speed control and static on radio mode

[Tubejunkie]

Hello everybody! I just got in a RC-550 and I replaced all the belts and the motor was pretty much frozen in place. So I put oil down the shaft of the motor and worked it in manually and left it alone for 4-5 days to finish working on a Sanyo. Lo and behold the motor sprang back to life and doesn't have any "cold" spots (dunno if i'm using that term correctly). The only thing is that it's running a bit slow, anyone know how to adjust the speed on this model?
Another separate issue is that on radio mode I get only static on AM & FM if anybody has knowledge about this issue you would be a lifesaver!
Thanks for your time!

 

[Radio raheem]

Not sure but there should be a small hole on the back of the motor, cant help with the other issue though

 

[Tubejunkie]

Thanks for your input Radio Raheem. I checked the back of the motor but on this particular one, it does not have a hole. Very confusing stuff . I'll double check and get back to you

 

[hopey]

Either the belts are too tight or your motor needs servicing or replacement. The tuner would need some work you have to find the faulty component; fusible resistorr could be.

 

[Tubejunkie]

Hopey, thanks for your advice and sorry about the delayed response. I replaced the belts accordingly as the old belts were still intact so I had an excellent reference. Turns out that the motor was just no bueno. Ordered a motor (CW) from Pacific Stereo and installed it, a little adjusting for speed pitch and now this thing is a killer box. I still have that fm static issue but I suspect that the IC "HA11251" has gone bad. I just ordered a cross reference "NTE 1490" off of ebay so when I get it and swap out the old one, I let you guys know. Thanks again.

 

[PostEnder]

Hi, Tubejunkie . Good to read that you’ve had success in rejuvenating at least part of a vintage boombox you acquired in (or just before) August 2020: a JVC RC-550. (Its atypical, “huge speaker/tiny speaker” design, its reputedly good sound and, of course, its edgy, daring “EL DIABLO” sub-title seem to always be a hit among collectors.)





I’ve often felt that the cassette-deck mechanism is the “must work” point of a boombox or mini-boombox – though I wouldn’t be happy with a boombox with a working tape deck and an unlistenably “staticky” or “dead” radio tuner. Perhaps especially if the radio tuner has shortwave (SW) bands, as JVC RC-550s tend to have. (As opposed to the “Japanese market” or “Asian market” Victor brand models that tend to have a “TV audio” band or two in lieu of SW bands.)





It’s been nearly nine months since you posted a message on this sub-forum in which you stated that you “ordered a cross reference ‘NTE 1490’ off of ebay.” Is that a microchip? Is it meant to replace an “IC ‘HA11251’ [that] has gone bad” in the JVC boombox? Do tell us: did you receive any of the other, ordered sub-components? Have you tried replacing any faulty parts with them and, if so, how did that project go? If you’ve tried to do the repairs, are there any pretty pictures or is there a YouTube video of the fixed-up beauty?





I might as well state here that I originally wanted to ask about the electronics supplier, Pacific Stereo, that you mention in your September 10, 2020 post here, Tubejunkie. Uh, is that the business located along Sepulveda Boulevard in Culver City, California, according to a Google search? I’m not sure if they have a website: you know, showing inside their store with walls lined with electronics supplies for portable and home stereos, etc. I’m thinking of trying (again) to get the cassette-deck mechanisms of both decks of my SANSUI CP-99W repaired. They still sound frustratingly slow, slightly wobbly and “half drunk,” perhaps especially during playback of audio that Tape Deck B, the recording deck, has recorded on Type II (high bias) cassettes. (Sigh …)





Well, again, good going with your boombox repairing (so far). More success is wished for you. And enjoy good music with the stereo. (Uh, not the type that the damnable EL DIABLO would gloat over.)

 

[JVC Floyd]

I would suggest that you try to trace the wires from the back of the cassette motor to whatever board they go to and then look close to where the wires go into the board to see if there are any adjustment pots and most likely if there is it's for the speed control for the tape motor.