HP-65 card reader "saga"

[aj04062]

I've been trying to source a fault on my 65 card reader.

I've checked the caps with an ESR Meter from a friend. Does anyone know what the calue of the CAP that connects Vbsw to Ground should be? This checked out at 15.9 micro F with a low resistance. The others checked out OK as well. I was doing a little research online and found some folks that claim they wouldn't trust an ESR meter on these and replace the CAPs anyways. Agree? Is there a series resistance anyone would recommend these caps be under?

[John Robinson]

It should be 2.2uF according to Tony Duell's schematics. Have you tested it removed from the circuit board ? The Kemets capacitors are generally very reliable, but they can fail.

Vbat should be the same as Vbsw, if they are then the cap shouldn't be a problem.

Cheers,
John