Noisy Matsuchita 12v Motor in a Yamaha MT8X - Broken commutator
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- Опубліковано 6 вер 2024
- I a received a Yamaha MT8X with an unusually noisy cassette mechanism.
When I opened the matsushita motor casing and desoldered the internal servo PCB, it turned out the commutator had split into three pieces.
The solution was to replace the PCB in a low speed new old stock matsushita motor with the PCB from the faulty high speed motor - this worked because the tape speed is dictated by the PCB. (Based on what I have seen so far, rush orientation controls the direction of rotation, the spinning armatures are the same in motors of the same brand, regardless of the speed or direction of the motor)
I wanted to avoid removing the plastic cap with the brushes set into it from the new old stock motor becasue its very fiddly to reseat the commutator between the brushes without bending the brushes - bending the brushes usually renders that part useless.
Here is a link to the video i made before about what is inside a 12 volt motor;-
• Whats inside a 4 track...
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I prefer to answer questions in the youtube comments where my answers can help more than one person, but if you need to share photos etc, you can message me via facebook.
/ tetrakan
I prefer to answer questions in the youtube comments where my answers might assist more than one person, but if you're shy or you need to share photos etc, you can message me via facebook.
/ tetrakan
Yep had 2 mt8x machines with this problem. If only I'd known you existed back then (lockdown)
This is next level deep. I saw one of these nearby for cheap. Runs but has weirdness and owner failed his own repair. Might be a nice waste of my time and money 😂
Not the easiest unit I ever worked on, but it’s your life I guess?
What info do I need to find a suitable replacement motor if this model is unavailable?
Let me have a look at the schematics and get back to you tomorrow
@@Tetrakan Thank you so much for what you do!
Hey so I ahd a look at the schematic, and the circuit is of the type where there is a loop with resistors in it joining to two of the four motor pins labelled A and B. I needed to check that becasue some yamahas including the little brother MT4X use a different and more complicated style of circuit to control motor speed. But with your MT8X you could buy a Mabuchi EG500KD or Eg530YD or EG500YD (I'm regurgitating the serial numbers from memory, so I might be a little off, get5 back to me if you can't find anythign on those search terms) and you'd probably need to adjust the trimpots on the MT89X or the variable resistor on the motor if the one you get hold of has such a feature, but those mdoels would basically work as drop in substitutes I think.
Any idea how to make the motor spin faster? tape keeps on getting stuck on the pinch roller after replacing the mmi-6h2lwk with another one I found on eBay. I think its moving to slow
Sounds like the smaller of the two belts and/or the idler tires ate loose. If you tell me which model you own I could narrow that down?
@@Tetrakan its on the mt8x, is that what model youre looking for?
@@btiemann6356 I've only seen that model once...remind me...is it a one two or three motor system under the hood?
@@Tetrakan 3 motor system
@@btiemann6356 I’m actually a bit I’ll and busy right now but if you could message me via Facebook, even if I can’t help you fix your issue I could put you in touch with a couple of techs I know who have spent a lot more time working on Yamaha stuff? Also search for “3rd island mt8x 10 second problem” or similar on UA-cam search - another yt tech who again is more familiar with the UA-cam stuff addressed this issue to do with the reel motor belt which *might* speak to this issue, but, again not a strong suite for me sadly.
Any chance I could get a more detailed tutorial on how to replace this? I have this problem and I own the replacement motor you recommended, but i am somewhat lost.
I've made a couple more videos you should find helpful, see this one ua-cam.com/video/KlaFh-X83sg/v-deo.html and this one ua-cam.com/video/h1BBVAtDtIo/v-deo.html it's a different brand of motor but the process for detaching the PCB is the same
So basically you took out the chip from the original motor and the replacement motor, you put the old chip in the new replacement motor and attached the replacement motor to the device?
I swapped the entire circuit board
How did you go about removing the golden motor pulley from the one?
If it doesn't pry off easily with a flathead screwdriver as a lever between the pulley and the motor case try heating the pulley with a cigarette lighter to loosen the adhesive