I have an HP41CX halfnut that when I put a magnetic card in a card reader, the motor of the card reader doesn´t turn on. Doing CAT 2 shows card reader present, so at least some power is available in slot 4 of the HP41CX. I have put a math module in slot 4 and shows all functions, the module works well. I have checked the card reader in an HP41CV and works perfectly. Maybe this problem should be a bad capacitor of the HP41CX?
thanks