Issues with magnetic card reader on HP-41CV

[rprosperi]

To add context to John's message, essentially 100% of 41 card readers have had their 'rubber' rollers erode and 'melt' into goo by this time. A handful of 41 card readers (3-4?) have been claimed to still be working w/o ever having the rollers changed, but if true, these are very rare anomalies and probably result from the readers being stored in some atypical conditions (especially dry? or cool? or... who knows?).

In addition to the roller material failing, there is motor shaft coupler (often called a clutch, which it isn't) which also fails in nearly as high a percentage of units, so when the rollers are changed, this coupler should be replaced as well; there are lots of articles, videos, step-by-step guides, etc. here on how to do these repairs DIY-style, and there are also members here, on eBay and on FB that will do this service for a fee.