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HP Forum Archive 19

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HP-65 card reader "saga"
Message #1 Posted by aj04062 on 28 Sept 2010, 8:57 p.m.

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?

Re: HP-65 card reader "saga"
Message #2 Posted by John Robinson on 30 Sept 2010, 6:40 a.m.,
in response to message #1 by aj04062

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

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