Hp-41C card reader - dead

[Vintage63]

I reassembled the reader but not put the top back on, plugged it in and executed CATALOG 2 to get the list of commands available on the reader. By the way who has a list of them with their meaning ?

The 41 can see it but if I insert a card nothing happens.

The motot by itself works.

At one point the screen went blank and the power button did not respond.

Removed the reader and after a while the power button worked again.
Could it be that I need new batteries? Not that these ones are that old.
I recall that, 30 years ago, the first time I plugged it in it drained the batteries, not this time.

Ideas ?
THank you
Marco