The spinner not connected to the motor is really hard to spin
i have a similar model. it's not exactly the same, it's a Sony Microcassette-corder M-10, fully working if it wasn't for the roller that is not the puller that is super hard to move, it does spin on the opposide side to rewind, but when i try to play a cassette it just get stuck, pushed and activates the auto shut-off mechanic of the corder... what can i do to let it loose?
long story short, the roller doesn't allow me to use the cassette recorder
you're techically correct for the motor since it does spin, but i think the belt is doing fine, if shared with the main one, the issue i think is the actual roller (the one you'll see in the clip) that is very hard to move and does quite a noise when moving