HP 41 Card reader problem

[AndiGer]

Cancuino,
Did you try the reader with another 41? Or another module inside your errorness 41? Especially in port 4, but also other ports?
Had also problems due to corrosion at the I/O block.

Did you see this thread?
http://www.hpmuseum.org/forum/thread-6626.html

Andi