I purchased my JVC-M90 back in 2014 for 1100 bucks. The tape deck was flaky however. it worked OK for a while. But then to get it to start again, you had to plug and unplug the boombox.. I had my friend service it and replaced the belts with the proper ones. It’s still had the same problem. He said that one of the plastic gears was wearing out. Because I know every time you turn on. The boombox. It goes through a cycle. With the tape deck. That probably prematurely, wears out the plastic gear. The problem is it’s impossible to get parts now. One would have to find a M90 but with the functioning tape deck. That might have a blown amplifier, but the tape deck part would be OK then take the good working deck and put it into the unit with the deck that needs replacement. If it’s a gear, a plastic gear, maybe with 3-D printing you could make a new one. Not sure about that. Any thoughts or ideas?
JVC-M90
- Thread starter prg333
- Start date
Thank you wow someone made up a lot of parts, especially those plastic gears that were impossible to get before. I wonder if that would solve my problem. My technician Lou said that’s what they needed. Last time he looked at it opened it up.
There is a black white (or silver/chrome) sticker on the original gear to provide a reflective surface. When spinning, the circuit is made aware because an optical sensor senses the pulses reflected back to it from a light source. The gear doesn’t include this sticker. The old one needs to be transferred over or a new one made, or the gear painted or something. Just fyi.
That’s good to know that you need that reflective special surface on the gear thank you. I guess you’d have to somehow get the reflective part on the new gear somehow maybe my friend who is very good technician could figure it out I think it’s the only way to make the tape deck play again.
I drew those M90 gears for someone else, and it turns out they weren't even bad in his deck, he just assumed they were bad.
You've posted the same thing about your M90 numerous times over the years, but every time you only say that your repair guy thinks it might be a gear, but it's not for certain. Is there any way to get more specific information about the problem? Are you 100% certain that it's a bad gear? If so, which gear is bad? Do you have pictures, or any more detail on the nature of the failure?
You've posted the same thing about your M90 numerous times over the years, but every time you only say that your repair guy thinks it might be a gear, but it's not for certain. Is there any way to get more specific information about the problem? Are you 100% certain that it's a bad gear? If so, which gear is bad? Do you have pictures, or any more detail on the nature of the failure?
My friend Lou is the only one has worked on the deck. I’m positive. He said it was a bad plastic gear. He told me it was getting worn out when he saw it and put in the belts the first time. I’m not sure which gear it was he didn’t take a picture of it. I think I told him to, but he did not. I’m sure he doesn’t remember the exact gear it is. Is it possible possible it might be something else I can’t say no to that. Unfortunately, there’s nobody else that I can find who has knowledge of the M90 and has the skills to work on it and fix the problem. If there was somebody anyone who was skilled enough with the knowledge, I WOULD have them work on my M90.
I asked my friend if it was fusible resistors he said no he checked that. The problem was it would be playing a tape and then it wouldn’t respond to any of the keys being pressed stop fast-forward rewind the tape head would just get stuck down. The only way to remedy it was to plug and unplug the boombox to get the head to go back to its normal position. I think there was a strange grinding sound. Sometimes someone said it wasn’t good here on this site to plug and unplug the boombox when the tape head got stuck down and I couldn’t get it to go back up by pressing any of the functions on the cassette deck. Because he said that upset the cycle of the tape. When you turn on the M90, it goes through a cycle with a tape inside. I don’t recall if it goes through that cycle with the tape, not in the deck. My friend Lou disconnected the tape deck inside. Because I think it was still without a tape inside going through some cycle.
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I understand you want it to work again, but if Lou can't fix it, I wouldn't trust his diagnosis. Anything we suggest is only going to be a guess anyway, and a competent tech won't care about your theories.
A lot of things have to work just right or else the deck is toast. It could be dirty buttons, a bad sensor or its transmitter, dirty leaf switches, cracked plastic somewhere, a jammed part from dried grease, a cracked or corroded PCB connection, a bad chip or transistor, etc. and it could be a combination of more than one issue.
My advice? Enjoy it as-is. If you don't want to open it and provide more details, or work on it yourself, then taking it to a tech with the skills to actually fix it is your only choice unfortunately. If the next tech you take it to confirms it's indeed a bad gear, and it turns out to be either the drive gear or reel gear, then tell them you have a link for a new one.
A lot of things have to work just right or else the deck is toast. It could be dirty buttons, a bad sensor or its transmitter, dirty leaf switches, cracked plastic somewhere, a jammed part from dried grease, a cracked or corroded PCB connection, a bad chip or transistor, etc. and it could be a combination of more than one issue.
My advice? Enjoy it as-is. If you don't want to open it and provide more details, or work on it yourself, then taking it to a tech with the skills to actually fix it is your only choice unfortunately. If the next tech you take it to confirms it's indeed a bad gear, and it turns out to be either the drive gear or reel gear, then tell them you have a link for a new one.
first thing i would do ls change the main flat belt, that a moron can do in 10 mins lol
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Yes, you’re right it could be a lot of different things. 40 years old this deck is already in the boombox. Parts just wear out things wear out. I’m enjoying it now as a radio and I can put a line in and play cassettes or an iPad
My 2 cents for the strange grinding sound M90- I find that the grease used to lube the actuating gear hardens over the years, and the gear does not engage (rotate) like it should (quickly) when the deck is actuated (button pressed). A grinding sound will happen until the gear catches and does a full cycle of the deck. This same process happens for each button press or power-up of the unit. The only way I know to solve this issue that I described is to disassemble the deck and remove the gear and old grease, then re-lube.
Eric
Eric
Sounds good you’re probably right about the grease and the gear. When they made these boomboxes back in the early 80s. They didn’t anticipate them lasting for 30 to 40 years they expected people would keep them for half a dozen years and then get rid of it and buy a new boombox if it broke within the warranty. They probably just gave out a new boombox instead of fixing the one that something went wrong with, it’s kind of amazing that some of these boomboxes were built well enough that the amplifiers in the radios still work. The belts pretty much are shot in these boomboxes, but if someone is skilled enough to replace the belts, they should be good for another several years.
I agree they didn't foresee these radios lasting 30+ years.
Manufacturers of just about everything (cars, electronics, appliances, etc.) have learned how to make things last just long enough to get through the warranty.
It's sad but true.