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HP Forum Archive 10

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HP-97 card reader
Message #1 Posted by Michel Beaulieu on 27 Jan 2003, 4:46 p.m.

I have a problem with my HP-97 card reader. I just repair it for the gummy wheel problem and reassembled it. When i put card in, the card is passing throught but i always get "error" message flashing one time and error is always lit after. How to get it work back. BTW i clean everything in the card reader assembly so no dirt in there..

Thanks Michel

      
Re: HP-97 card reader
Message #2 Posted by David Smith on 27 Jan 2003, 5:54 p.m.,
in response to message #1 by Michel Beaulieu

The problem is most likely a bad tantalum capacitor. It is usually a small blue colored dipped tantalum. It is used to filter noise from the power supply. Over time it develops a high ESR and quits filtering, even though it will test as good. The value is not very critical. I have used anything from 3.3 to 10 uF. I think the original is around 4.7 uF. I usually use 6.8 uF because the local capacitor store had lots of them for cheap.

            
Re: HP-97 card reader
Message #3 Posted by Michel Beaulieu on 27 Jan 2003, 7:55 p.m.,
in response to message #2 by David Smith

Can i use a normal electrolitic capacitor? Is it the capacitor connect to the motor terminals?


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