HP 82104A "CARD ERR" error

[Erik-M]

My personal experience:

- bad batteries, check first with a new set
- too much pressure, the axis of the plastic gear with the roller is concentric, if you turn it and position the little dot on the screwhead opposite the motor the pressure is minimum. some o-rings are a little larger than the original roller.
- slipping o-ring, clean the metal axis very well with IPA and fix the outer o-ring (or both) with a very little superglue
- dirty gears, clean with IPA and use a very little oil suitable for plastic on the gear

other possibilities:

- slipping coupler between motor and wormgear, rebuild or use a little superglue
- dirty recordinghead, the remains of the original roller can be everywhere, clean very well with IPA
- head out of alignment, I have no experience on how to solve this
- worn out bearing of the wormgear, a little bit of molygrease in the hole where the axis rests can solve this. It is reported that the cardreader makes a bad noise if this is the case but I have no personal experience.

I am not an expert on cardreaders but I repaired a few and had some that had card errors after the repair. I could fix all of them.