Older 67 card readers and 65 card readers

[teenix]

Looking at the circuit diagrams from Tony Duell, the capacitors are 2 x 22uF, a 6.8uF, and a 3.3uF on the motor. You could replace them with tantalum ones, say 16 - 25V rating.

There looks to be an extra 3.3uF cap on the 97, looks like it is used as a power up reset.

The red mark would indicate the positive end.

cheers

Tony