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HP Forum Archive 15

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Lost key bounce (Pioneer)
Message #1 Posted by Eduardo on 16 Jan 2006, 6:40 p.m.

Hi all,

A sad thing just happened to my HP 32SII: I left it abandoned in a box with other stuff for about a year and now the ENTER key has totally lost its bounce. In fact, it takes the gentlest touch for it to register a keypress, and sometimes it gets stuck (remember that in a 32SII the name of a key appears after it's pressed for a half-second or so? Well, sometimes I take my finger off the ENTER key and the display is stuck showing ENTER). Actually, also the keys immediately above an below ENTER, namely STO and XEQ, have lost most of their bounce, but they are still what I'd call usable.

I immediately thought about FixThatCalc.com but their web site warns that key bounce is not generally repairable. Should I declare my 32SII dead? Anybody has experience with this? (or can at least offer emotional support)?

Thanks, Eduardo

      
Re: Lost key bounce (Pioneer)
Message #2 Posted by Randy on 16 Jan 2006, 10:08 p.m.,
in response to message #1 by Eduardo

It's a lost cause... the keyboard probably had something heavy pressing against the Enter key for some time and flex dome has collapsed. I've seen it in units get very hot as well - the top plastic dome sheet of the keyboard has been oriented and the heat/constant tension relives the stress that formed the dome. Once flat, there's no going back... sorry.

Edited: 16 Jan 2006, 10:11 p.m.

            
Re: Lost key bounce (Pioneer)
Message #3 Posted by Eduardo on 16 Jan 2006, 10:58 p.m.,
in response to message #2 by Randy

May it rest in peace then...

:'-(

Thanks.

Eduardo

                  
Re: Lost key bounce (Pioneer)
Message #4 Posted by Eric Smith on 17 Jan 2006, 2:25 a.m.,
in response to message #3 by Eduardo

If you're going to retire it, would you consider selling it inexpensively? I'd like to get one for reverse-engineering purposes (ROM dump), but I'm not willing to pay big bucks for a good one on eBay and then destroy it.

                        
Nonpareil and dead 32Sii's
Message #5 Posted by Randy on 17 Jan 2006, 5:03 p.m.,
in response to message #4 by Eric Smith

Eric,

I have several dead ones kicking about, they all have broken keyboards. I could mount the LCD in a 10B frame and while the keys wouldn't match up with the functions, it would work. I also have some 10B's and 20S's that I would donate to the effort if you wanted them. Just email me at randy at fixthatcalc dot com

                        
Re: Lost key bounce (Pioneer)
Message #6 Posted by Eduardo on 18 Jan 2006, 10:09 a.m.,
in response to message #4 by Eric Smith

I think I'll keep it. I do not really use it nowadays, so it is more of a "collection item". Besides, it is borderline usable (more on the "not usable" side). Maybe I'll get one of the older (orange and blue shift key) models, though eBay is outrageous...

Eduardo

      
Re: Lost key bounce (Pioneer)
Message #7 Posted by Paul Brogger on 17 Jan 2006, 5:30 p.m.,
in response to message #1 by Eduardo

I've repaired a few Pioneer keyboards.

I disassemble, including the PCB (though I think you may leave the LCD in place). I've shaved off the tops of all the heat stakes hodling the metal backing plate to the front of the calc. Then, either clean the sandwich layers or replace them with parts from a disposable (algebraic, business, etc.) model. On one, with worn contact material in the mylar domes, I re-inked the dots with a conductive ink pen. (I don't have much experience with actually using it, so I don't know how long the ink adheres . . . )

Then I've just pressed the sandwich back together and re-melted the remaining portions of the heat stakes with a very pointy soldering iron. Enough plastic is forced out to restore the attachment.

But again, I don't have any long-term experience with actually using these restored keyboards, so your mileage may vary. But the keyboards did, in fact, work. And with fully-replaced layers, they should be almost as good as new.


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