HP 41 Card reader problem

[Geoff Quickfall]

Software or hardware?

Software:

Easiest to fix but tedious. Try a memory rest of calculator. Then try card reader.

Hardware:

Calculator: When inserting card reader entire shell can flex. With weak screw posts or loose screws the module/battery block connection and to a lesser extent the keyboard PCA connection may become intermittent causing erroneous displays or no display. Lots written up on screw posts in the archives.

Card reader: I take it this reader has a new pinch roller (o-ring or flex tubing). May be a connection on the plug or dirt. Clean contacts on both the male (calculator) and female (card reader module.

This is like a doctor diagnosing over the phone, very iffy at best. Try the above one at a time, starting with machine reset, cleaning modules, checking screw post integrity, cleaning module/battery block contact, PCA contact and keyboard contacts and if good then tightening screws (gently).

Geoff