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HP Forum Archive 21

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How does the HP-97 printer paper feed work?
Message #1 Posted by Harald on 30 Mar 2012, 4:29 p.m.

I have started repairing the HP-97 I mentioned a bit further down. I have a problem with the printer. The paper feed does need a little help by pulling the paper manually. I have taken it appart and all the gears (at least all three I can see) are ok. And the head moves as it should. But I do not understand how the paperfeed works? Can anyone help?

Also, I have replaced the gumy wheel and the cardreader pulls the card through fine. But I get an error when trying to read a card. Not sure if it is the reading or the writing that is the problem. Should it be able to read cards written by an HP-67? In that case, I suspect reading doesn't work. Any thoughts on what to check?

Cheers, Harald

      
Re: How does the HP-97 printer paper feed work?
Message #2 Posted by Harald on 30 Mar 2012, 7:49 p.m.,
in response to message #1 by Harald

OK, I have worked out how it is supposed to work. I think it is just the rubber wheels that have hardened. How do I replace them? And what with? Has anyone done this yet?

Edited: 30 Mar 2012, 7:49 p.m.

            
Re: How does the HP-97 printer paper feed work?
Message #3 Posted by Ignazio Cara (Italy) on 31 Mar 2012, 3:30 a.m.,
in response to message #2 by Harald

Hi Harald,

I have did the job in this mode, take a look at the following. slideshow.

The silicon o-ring are 8x2 mm (OD=8;ID=4).

Let me know if it's quite understandable.

Regards

Ignazio

Edited: 31 Mar 2012, 3:33 a.m.

                  
Re: How does the HP-97 printer paper feed work?
Message #4 Posted by Harald on 31 Mar 2012, 9:35 a.m.,
in response to message #3 by Ignazio Cara (Italy)

Thanks for that! Seems like a good solution. However I wasn't prepared to take drastic measures yet. Insted I tried to scrape the hardened surface off the rubber wheels, and had a bit of succes. The paper is beeing pulled through now, but not quite straight. Maybe I can improve on that. If not, I'll try your approach.

Cheers, Harald

      
Re: How does the HP-97 printer paper feed work?
Message #5 Posted by aurelio on 31 Mar 2012, 9:01 a.m.,
in response to message #1 by Harald

For what regards the card reader issue I remember that I read with a 97 a card written by a 67! Regards

            
Re: How does the HP-97 printer paper feed work?
Message #6 Posted by Harald on 31 Mar 2012, 9:31 a.m.,
in response to message #5 by aurelio

Thank you! I just found that out myself,^too. The cardreader is now working! Somebody had messed about with the adjustment of the spring contacts and then used a bit of tape to jack up the PCB. I had removed that tape when doing the repair, but not re-adjusted the contacts. Now that I have done that, it is working!


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