HP 41CV card reader

[John Bjornholt]

Does anyone have any technical info on the HP41CV card reader, such as schematics, block diagrams, trouble-shooting procedures, etc? I recently sucessfully repaired the drive wheel on mine, but now I get a "malfunction" display when it tries to read a card. I have an o-scope and other necessary test equipment to check for waveforms, voltages, etc.

[PeterP]

IIRC, TOS has the Card Reader Repair Manual from HP. Also a Google on 'repair card reader site:www.hpmuseum.org' or something along these lines will bring up many threads with potentially useful information. There recently was one where a defect cap was the source of reading problems.

HTH

Cheers

Peter

Edited: 4 Feb 2009, 12:03 p.m.

[Roy Welch]

Peter, what is the IIRC and TOS? I also need to get the LED part I discussed with you. Maybe a schematic or parts list is available.

Roy

[Jeff O.]

IIRC - If I Recall Correctly

TOS - That Other Site. Another HP related web site. It is a long story, but suffice it to say that out of respect to the owner of this web site, links to and direct mention of the name of that other site is not done.

[Roy Welch]

OK, thanks. The LED is an IR type I'm told. The lens of the LED was shattered so I can't see the flat side showing the polarity indication. That's why I need the schematic.

Roy

[Carl Vanden Bulcke]

Hi,
I have a similar problem with the drive wheel where the friction wheel seems to have "dissolved". Could you let me know how this could be replaced/repaired? Are parts still available from hp?
Thanks for your help!
Carl Vanden Bulcke _ Belgium

[Michael de Estrada]

This is commonly referred to as the "gummy wheel", and it can be repaired either with plastic tubing or O-rings. There are several articles under the "card reader repair" heading in the articles section of this forum. You can find suitable O-rings on ebay, and I have had success with this method on several card readers. Parts are not available from HP. Also, I don't know if the HP-41 series card reader has a motor clutch similar to the HP-65 or HP-67, but if it does, it may also need repair.

[Ignazio Cara (Italy)]

The coupling between motor shaft-worm gear is surely the same of 65, 67 and 97.

regards

Ignazio