Posts: 174
Threads: 32
Joined: Apr 2006
I have seen (heard) this happen when the motor is slipping inside the small gear that is attached to it. There is a small plastic insert inside this gear that acts like a clutch. It slips if there is too much torque required to drive the card.
I would take the card reader apart and clean the teeth on both gears and use a small drop of "super glue" cyanocrylate on the motor shaft if the gear is too loose on it. Otherwise, remake the plastic insert. There are some consequences to gluing the gear to the shaft however. The motor no longer has a clutch to protect it if the reader gets jammed up and you need to make sure the glue does drip down into the motor.
The other possible reason for noise might be that the motor has become loose or is not tightened evenly (i.e is cocked) to the calculator. There are two small screws that retain it to the calculator. Make sure these are tight and one is not tighter than the other one, which will cock the motor.
Hope this helps.