Sony CFS-230 No spin with tape in

[retrosteamknight]

First post on the site, the reason why I made an account here to begin with.
I bought a used Sony CFS-230 boombox from a thrift store for $7. Radio works brilliantly, but the reels for the cassette deck do not spin. With a professional technician quoting $80 for a diagnostic, I figured I would be better off pulling the thing apart. After removing the shell and dusting off the internals (that was a lot of dust, uff da) I began inspecting the behaviour of the tape deck and found that the reels spin when no tape is loaded, as well as when the pinch roller is pushed out of the way. When the pinch roller is left to rest on a cassette, there is a second of spin-down followed by silence. Even the belt stops turning.
Pulling the radio apart even further shows that the internals look relatively clean and the belt is still intact and unmelty. I will be replacing that anyway while I'm in here, as I don't know its remaining lifespan. I've seemed to have narrowed down the issue to the motor, but I'd like a second opinion before I make any purchases. The motor inside is a Mabuchi EG-500AD-9B (9v DC 2400rpm) motor, which I can only assume was not in there when it left the factory. An exact replacement is expensive to get through eBay. If I match the voltage, RPM, and torque of the close-to-death Mabuchi, could I replace it with something similar but locally available?

 

[Jack_Dowdy]

My best guess would be to clean the motor contacts first and then give it a shot. Sometimes a little cleaning can go a long way.

I'm not the most expierenced guy here, so lmk if it still doesn't work

 

[retrosteamknight]

My best guess would be to clean the motor contacts first and then give it a shot. Sometimes a little cleaning can go a long way.

I'm not the most expierenced guy here, so lmk if it still doesn't work

From what little I can clean of the motor without learning how to solder and desolder (Mind you, I wouldn't mind an excuse to finally learn to solder), the issue is still prominent. Free spin with no tape in, and no spin with tape inside. I am impressed, though, that I was still able to take the motor completely out and put it back inside without anything breaking. This is a first for me. Very inspiring. Lmao.

 

[retrosteamknight]

Update to the theatre here, after waking up this morning and trying to replicate the issue, I managed to get the tape to play... But way too slowly. Pat Benatar sounds like a malevolent spirit. Trying to replicate the issue just now, it took a few tries before the tape was able to play again, at that same too-slow wailing speed.
Video Example 1
Video Example 2

 

[retrosteamknight]

I'd like to take the time to apologise to the people who have watched me struggle. I've at least put on a good show.
I've cleaned the belt with some nice soapy water and dried it completely. I've also cleaned the pulleys as well. Reseating the belt has left the tapes playing faster, but not quite as fast as it should be.
An example can be found here. Contrast with Video Example 1.
Of course, I recognised the age of the belt and have ordered a replacement. Should I go ahead and let the replacement belt ship, or should I go directly to the motor speed control and adjust until it fits? Given that a simple clean restored the tape to such a speed, I don't quite know if it's already as fast as the belt can provide, or if the current (old) belt is still the thing that is holding it back.

 

[floyd]

I'd like to take the time to apologise to the people who have watched me struggle. I've at least put on a good show.
I've cleaned the belt with some nice soapy water and dried it completely. I've also cleaned the pulleys as well. Reseating the belt has left the tapes playing faster, but not quite as fast as it should be.
An example can be found here. Contrast with Video Example 1.
Of course, I recognised the age of the belt and have ordered a replacement. Should I go ahead and let the replacement belt ship, or should I go directly to the motor speed control and adjust until it fits? Given that a simple clean restored the tape to such a speed, I don't quite know if it's already as fast as the belt can provide, or if the current (old) belt is still the thing that is holding it back.

I would put the new belts on then adjust the speed . if it's never had new belts it's probably over due.

 

[retrosteamknight]

I would put the new belts on then adjust the speed . if it's never had new belts it's probably over due.

Good point there. I'll let the new belt ship, and I'll also probably order a calibration tape as well, while the belt ships. Mind you, I'm still underneath the $80 initial quote, so... And I'm learning.

 

[floyd]

Good point there. I'll let the new belt ship, and I'll also probably order a calibration tape as well, while the belt ships. Mind you, I'm still underneath the $80 initial quote, so... And I'm learning.

If you can change the belts yourself you will save money and hassles later on with the belts always causing potential problems. It's one way to eliminate worn belts as unwanted problem down the road.

 

[floyd]

One other thing is if you have a tape you heard the song 3000 times before you can use that as a reference to adjust the tape speed . it's not perfect but to me I can tell when it sounds right lol.

 

[Hajidub]

First order of business, even if a used deck works, is clean the tape path and replace the belts. Idler tyre eventually next if FF/REW gives you problems.