HP-71b Card reader "WRN: R/W Error"

[Nenad (Croatia)]

Thank you for the text you pointed to. The most important sentence from the text in my case is: "Since even blank cards must have timing tracks and data tracks, every card sold must first go through this recorder..." So, may new cards may also be defective.

So, I have on my disposal the HP-71b, its card reader, a set of 5 cards and one red abrasive card. I tried each and every of the cards (both left/right sides: the one with HP logo and the one without), obtaining always the same result: "WRN: R/W Error"

What should I do next to find out whether the problem lies in the card reader or in the cards?

Thanks in advance.

(11-11-2018 09:42 PM)Dave Frederickson Wrote:  No. The timing track on the cards was written by a special machine at HP. See the HP Journal issue for the HP-75 which uses the same card reader, June '83, p. 20.