Just bought a HP-67 calculator at an auction

[rprosperi]

(07-29-2020 11:20 AM)Harald Wrote:  

(07-28-2020 11:43 PM)Namir Wrote:  As for the magnetic card reader, it is most likely need repair because the card reader deteriorates with TIME, regardless of how pristine the calculator looks.

Namir

Well, if the card read has NEVER been used, maybe there is a chance it still works. I suspect the deterioration of the wheel is triggered by contamination. Maybe it gets contaminated by the cards, but maybe just air getting in is enough. Would be interesting to find out...

Interesting comment Harald! I have seen a few people over the years assert that their 67 card reader works, never having been repaired. Though somewhat suspicious that it was more likely they were simply unaware of the repair, this theory would explain it. It would indeed be interesting to know.

It's interesting that this problem, common to all old HP (and TI) machines, remains pretty much unexplained, other than the overly simple "the rubber eventually turns to goo", which is not something commonly happening to other similar vintage products. My cassette deck has bands and capstans with rubber 'wheels' which may have hardened or gotten brittle, quite the opposite of turning to goo. I'd like a materials science engineer to comment if this is really typical or perhaps a unique phenomenon.