Sanyo m9998LU the tape engine does not work

[aloisek]

Hello, I own this radio. The cassette engine does not work.
I've read before that a resistor may be to blame.
But now I can't find where I read it.
Does anyone know what resistor is?

 

[hopey]

Try testing it with a 9v battery

 

[baddboybill]

Hello, I own this radio. The cassette engine does not work.
I've read before that a resistor may be to blame.
But now I can't find where I read it.
Does anyone know what resistor is?

They were most likely speaking of the variable resistor which controls the speed of motor. Most of the time it’s the electronics of motor that go bad. First test the motor wiring for power with a meter. If it has power then most likely the motor is is bad.

 

[aloisek]

 

[aloisek]

This is analyzed and discovered today. Don't know the value of that little resistance? The big one is about ok has 100 ohms.

 

[Tinman]

Yeah, they look smoked.
Maybe someone with a service manual can help you out.

 

[aloisek]

I have already obtained a manual for the LU version. R736 100ohm is OK, R742 3.3ohm is KO measured approx. 500kohm. I'll try to exchange and see. I'll still change the belts, he reached for him and stayed glued to his hands.

 

[baddboybill]

They definitely look like fusible resistors

 

[Superduper]

The m9998 motor is not adjustable if memory serves me correct.

 

[aloisek]

After connecting the battery, the motor rotates.

 

[aloisek]

Hello. So replacing the wrong resistor didn't help. The engine does not spin. Motor voltage 0.4V. If anyone has an idea they can share it.

 

[Superduper]

1: check L701 out of circuit, make sure it's not open
2: check C728, make sure it's not shorted
3: check C733, make sure it is not shorted
4: replace Q710
5: oh and make sure you are not testing the wrong motor wire for voltage.

it would help if you would test and post the emitter voltage of Q710.

 

[aloisek]

True Q710 is wrong. The others seem ok.
I'll replace and let me know how it works.

 

[aloisek]

after connecting + battery to the emitter motor works.

 

[aloisek]

The super engine is spinning. Playback works without error. But rewinding is a weak tape that is hard to spin. I was giving new rubber bands, maybe some are weak. I'll have to disassemble again.