HP-71B MultiMod ROM Emulator - Issues ?

[Dave Frederickson]

(03-27-2021 03:35 AM)Sylvain Cote Wrote:  All three modules work on S/N: 2713A00041 but none works on S/N: 2410A00146.
I know the card reader port works on S/N: 2410A00146 because it usually hosts a working FRAM71 module.

This could still be a contact problem. You might try giving the card reader port pins a good cleaning with DeoxIT "D" formula or a pencil eraser.