Trying to get my old HP 65 in full working condition. It's been stored away a number of years. I've cleaned out the battery compartment and ordered new Ni-Cd batteries to restore the battery pack. I have also opened up the case and checked the Card Reader. One of the screws attaching the motor to the chassie was completely loose and the other partially loose. I reattached these. Now the problem: When inserting a card nothing happens - the motor doesn't run and the display flash "0.00" and gets dark. Pressing "Clx" resets this. What would the next step be in order to fix the Read Reader? I know that the Reader worked before putting the calculator in storage a number of years ago.

{moderator repost}

As it happens, I just finished servicing (gummy wheel) an HP-67 card reader last night...assuming things are similar on the HP-65 card reader:

There 9 (I think) wires that plug into the card reader controller board. They plug into odd litter terminals that protrude vertically from the board. It's easy for these wires to come unplugged!

The first check would be to make sure the red and black wires from the card reader motor are securely plugged in. On the 67 card reader, the read and black power leads from the batter/AC are right next to the card reader motor leads, and the black leads from each are adjacent (from the top of the controller board it's power red, power black, card reader black, card reader red).

If that's not it, it could be a blown controller board or a problem with the little switch the card pressed to activate the motor. The latter consists of a tiny nylon ball that presses copper fingers onto a contact.