Hp-41C card reader - dead

[Vintage63]

Good evening / morning / afternoon everyone.
I have been an HP-41C owner since university, let me think, 38 years ago. Time does fly.
I have 3 Memory Modules plugged into the back of the 'box', I've inserted the Card Reader, 82104A, ehich had been sitting around for years in its box.
Batteries have been replaced a few months ago after the previous ones 'died'.
The card reader does not move at all when I insert a card.
What can I do? I recall that when the card reader was inserted, ages ago, it drained the batteries but then worked properly. This time nothing of the sort happened.
I've read the various tutorials on how to replace the gooey card puller, but nothing about the motor.
Is there any documentation available or anyone that knows what to do ?
I've got no problems at fixing 'old' stuff, in fact I do some fountain pen renovations, so working on it should not be a problem.
If the worst come to the worst I'll bin the reader and that's that.
Thank you
Marco