Restoring a HP9830B calculator.

[MattisLind]

Today I received five key switches and the last missing key top from a fellow HP9830 collector. Thank you very much! This is the reassembled complete working keyboard:



I tried the REWIND button. But there were nothing but a spinning sound. No motion. I think that there should be a clicking sound from the solenoids. Either there is some fault or they were just stuck.

When I looked into the tape unit I found that the rubber on the wheels were quite worn, so I need to fix that.