The device does not play because the tape does not touch the heads. There is something hanging and misaligned from the heads. Rewind and coil correctly.
I think that the left motor whose function is to stop the reproduction, in addition to rewinding, does not brake enough so it does not create tension. When I brake the left coil a bit with my hand, it reproduces correctly.
The drag rollers and the winch make good contact.
I do not know how I can adjust the motor voltage, (if it was the cause) nor its value.

I would appreciate any help or comment.