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HP 97 printer repair with HP 82143 parts?
05-25-2016, 12:20 PM
Post: #1
HP 97 printer repair with HP 82143 parts?
I have been playing with my 97 today and discovered that the paper feed is not working properly anymore.

[Image: 20160525_103801l8jto.jpg]

Now I am wondering if I can simply aquire a 82143 printer an replace the printer mechanics with the 82143 mechanics. Or is this not a drop in replacement?

Cheers,
Harald
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05-25-2016, 02:40 PM
Post: #2
RE: HP 97 printer repair with HP 82143 parts?
It is not a drop in replacement motor speed control is different, uses a belt to drive the lead screw instead of gears. You can however use a lot of the mechanical parts, except the lead screw and motor, and you can use the frame but there are a couple projections on the 82143 frame you need to shave off.

I have resolved the feed roll issue by removing the old hard tire and the plastic flange under it and replacing it with a bit of silicon tubeing.

Paul
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05-25-2016, 07:45 PM
Post: #3
RE: HP 97 printer repair with HP 82143 parts?
the HP82143A printer chassis works nicely in the HP-97. As paul already mentioned, there are some tweaks required to adjust the HP-97 control electronics to the different printer speed. see attached photos of what i did.
IIRC, the 82143A printhead electrical data differ from those of the HP-97 printhead, therefore it is required to remove the 82143A printhead and mount the HP-97 printhead into the 82143A chassis instead. to adapt the print speed and print line length, you have to change two resistors on the controller boards, see pictures. it is best to use trimpots first to find the best fitting resistance values and then replace the trimpots with fixed values.
(note the excellent quality of the printout!).
   
   
   
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05-25-2016, 09:47 PM
Post: #4
RE: HP 97 printer repair with HP 82143 parts?
Thanks to both of you! I'll have a look for a printer and see how I get on.

Harald
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05-26-2016, 09:05 AM (This post was last modified: 05-26-2016 11:33 AM by isanchez.)
Post: #5
RE: HP 97 printer repair with HP 82143 parts?
Hi,
I have plenty experience in repairing HP97 calculators.
You have to replace the paper advance rolls. They trend to disgregate or create "plain faces", that make that i.e. each four lines the interspacing is bad.

I do recommend to use the squared o-rings offered in ebay for the card reader repair. They work very well. I have repaired many 97s and more HP41 printers (both are substatially the same and have this problem)

If you need any help do not hesitate to contact me. I can provide you pictures about how to do it, or you can send it to me (I am located in Spain) It is a bit difficult to do it the first time, as you have to adjust the paper advance axis to work properly...but once done, you will get your printer back for many decades!!

I do not recommed to use the tracking rolls from the HP41 printer, as all tracking rolls trend to disgregate with time. This is not a permanent solution. In any case, both are interchangeable...but the potential problem is still there, and will come back.

Regarding the HP41 printer and the 97 compatibility... you can exchange the frame perfectly, taking into account that the motor transmission mechanism is different, as mentioned. I have not had the need to break any part to adjunt the frame into a 97..it fits fine. I had to do this because the guides that keep in place the transparent plastic viewer in my 97 were broken and it did not keep in place as paper advanced.


Good luck and kind regards
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05-28-2016, 10:07 AM
Post: #6
RE: HP 97 printer repair with HP 82143 parts?
(05-26-2016 09:05 AM)isanchez Wrote:  Hi,
I have plenty experience in repairing HP97 calculators.
You have to replace the paper advance rolls. They trend to disgregate or create "plain faces", that make that i.e. each four lines the interspacing is bad.

I do recommend to use the squared o-rings offered in ebay for the card reader repair. They work very well. I have repaired many 97s and more HP41 printers (both are substatially the same and have this problem)

If you need any help do not hesitate to contact me. I can provide you pictures about how to do it, or you can send it to me (I am located in Spain) It is a bit difficult to do it the first time, as you have to adjust the paper advance axis to work properly...but once done, you will get your printer back for many decades!!

I do not recommed to use the tracking rolls from the HP41 printer, as all tracking rolls trend to disgregate with time. This is not a permanent solution. In any case, both are interchangeable...but the potential problem is still there, and will come back.

Regarding the HP41 printer and the 97 compatibility... you can exchange the frame perfectly, taking into account that the motor transmission mechanism is different, as mentioned. I have not had the need to break any part to adjunt the frame into a 97..it fits fine. I had to do this because the guides that keep in place the transparent plastic viewer in my 97 were broken and it did not keep in place as paper advanced.


Good luck and kind regards

Thanks for the comprehensive description!
That makes sense. I will attempt the o ring repair then.

Cheers,
Harald
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