|Re: HP-41 card reader producing strange sounds|
Message #2 Posted by Vieira, Luiz C. (Brazil) on 24 Apr 2004, 11:46 p.m.,
in response to message #1 by Miki Mihajlovic
I remember having the same problem, but mine did not write cards correctly, although sometimes it could read.
As you have the documents about replacing the gummy whell, note that there is a worm gear (endless thread) mounted in the motor's axle that rotates the driven (pulling) gear and I had two readers with this wornm gear slipping when the axle rotates. But as I mentioned, the most immediate symptom is that the cards slow down their speed when pulled. When the reader is reading cards it may not be a big problem if the speed does not vary too much (there is a separated "sync" track recorded beside the data track), but when the reader is recording cards, these cards may not be easily read. In fact, even if the sync track is not be uniform, the reading process may be performed by a "normal" card reader, but it may be way too irregular that the reader with problems may loose data when reading them back.
Have a look at the article about the gummy wheel under the heading "All clean?". Read the last paraghaph and you'll have tips on how to fix this with cyanoacrylate glue.
Hope this helps.
Edited: 24 Apr 2004, 11:47 p.m.