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Is there anyway to fix Pioneer series key SNAP???
Message #1 Posted by Steve on 30 Nov 2002, 10:11 p.m.

Is there any way to fix keys that SNAP on a Pioneer (17Bii, 32Sii) series HP? I'm not talking about the normal clicking sounds, it's a SNAP that can be heard across the room. It doesn't seem to get any better with use. Some units have it, and some don't. Is it a manufacturing defect in the keypad? Thanks,


Re: Is there anyway to fix Pioneer series key SNAP???
Message #2 Posted by Randy Sloyer(US) on 1 Dec 2002, 12:26 a.m.,
in response to message #1 by Steve

Are these nasty cracks coming from a newer Indonesian unit? I would bet money on it. I have not seen a early USA or Singapore unit snap. Unless of course you've spilled some soda into the keyboard, but then your calculator would probably not be working as this is the fastest way to disable a pioneer, since the batteries never seem to die :)

Before I tell you I don't have an answer for you, let me tell you what I've seen in dissecting several flavors of pioneers. Perhaps that will get some discussion going and someone may have or come up with a solution. The current keyboards are comprised of 4 identically sized mylar sheets that sit atop a formed metal sheet that is the skeleton of the calculator. The bottom sheet is just a spacer with a hole in each key position, the second layer is a rather novel double sided flexible circuit that is guts of the keyboard. The third is again another swiss cheese spacer sheet. Right under the key is the top and final layer, the dome sheet. The sheet has small domes formed into the mylar onto which a flexible film resistive dot has been printed.

When you press a key, the dome deforms, allowing the resistive dot to collapse through the top spacer layer and contact the conductive sheet below, completing the circuit. When the dome snaps back, you sometimes get a clicking sound. I believe this is present from the beginning and it just will not go away with use. I have a newer 42S that has this annoying habit. I've been banging on it for 6 months now and it has not changed a bit.

I think there are at least two possibilities for the snapping. One is a change to the dome sheet. I've looked at both old and new sheets and they are made of the same 0.005" mylar. I have not measured the force required to deform the domes as I don't have the necessary equipment, but it is possible that the orientation is different in the sheet, requiring higher forces and the equal higher force return, resulting in a snap.

The other is related to dome force, that is, the dampening of the return of the dome. One thing I have noticed in the various units that I have opened is that I believe HP changed the formulation of the case material over the production life-cycle. The early machines had a harder finish, perhaps from a higher styrene content, to the current softer material on the newest machines. This change in material changes the way the keytop rebounds from the dome popping back. The newer, softer material does not dampen the force as well, resulting in the snap of the mylar as it comes back to it's original pre-stressed position. Just hold your finger on the key as it comes up, just a bit, and the snapping should not occur.

Just my 0.02 cents worth. I have several different keyboard mylar sheets in the pioneer parts box and would be happy to post some photos if anyone wants to continue this. I would like to find an answer myself...

Re: Is there anyway to fix Pioneer series key SNAP???
Message #3 Posted by Raymond Hellstern on 2 Dec 2002, 6:47 a.m.,
in response to message #2 by Randy Sloyer(US)

Hi Randy,

in fact it's not only the new Indonesian units...

I had a 42S Rev A from ca. 1989, which had that annoying loud & sticky CLICK.

The reason for this effect are sticky or broken plastic domes. When talking of domes, I mean the whole outstanding construction, not only the small inverted dome inside.

These domes are responsible for the normal tactile feedback as well as for the real 'key-pressed' signals.

When you press a key which has this symtome you'll first feel the normal click, when releasing the key, you'll normally first feel the normal depressing click, but in case of an ill key the loud CLICK will be a bit delayed, when the force of the dome becomes greater than the adhaesion to the pcb. Alternatively, there'll be a hard CLICK when dome is broken.

BTW: Back then I exchanged my loud 42S for a new one by HP in 1999, and Indonesian unit, which is brand new, but of significantly poorer quality than my old unit.

Imagine how happy I was this year when a co-worker gave me his brand-new Rev A 42S for free!



Re: Is there anyway to fix Pioneer series key SNAP???
Message #4 Posted by Karl Schneider on 1 Dec 2002, 2:32 a.m.,
in response to message #1 by Steve

Steve --

I would agree with Randy Sloyer's question above, in that your 32Sii is likely an Indonesian-made unit with the white bezel and green/lilac shifted functions.

I have a 1989 42S and a 1993 17Bii (both Singapore) and a 2001 32Sii (Indonesia). Only the 32Sii has the annoying "snap", which seems to result from a tab on the keys striking the underside of the face. Not all keys do it, but it's probably due to a cheaper manufacturing design or process.

Re: Is there anyway to fix Pioneer series key SNAP???
Message #5 Posted by Steve on 1 Dec 2002, 6:59 a.m.,
in response to message #4 by Karl Schneider

I also noted that shifting the case around would fix the problem in certain key, but then cause problems in others. What I mean is prying open the case near the snapping key a few MM (the Pioneer cases accommodate this quite easily!) would change the tension on the keypad unit enough to move the problem to another key.

I guess this goes back to how HP quality has really dropped off in recent years. I would hope these units wouldn't pass QA even at Casio.


Re: Is there anyway to fix Pioneer series key SNAP???
Message #6 Posted by Harvey on 11 Dec 2002, 12:58 a.m.,
in response to message #1 by Steve


I've got a 42S that is also experiencing "snap" and "stickiness" problems. At least on my unit, I can see dust down around the keys below the metal faceplate. I haven't used this unit for the past few years because it was experiencing "missed" inputs on keypresses on a couple of the keys. I'm wondering if the keypad needs a good cleaning. I'd dearly love to get this unit back in operation again.

I've been contemplating taking this unit apart; I've read Paul Brogger's posts about opening up the 42S. It seems like taking the keypad assembly apart will require a step of faith (and more than a bit of skill). Is this the only way to get at the keypad (i.e., via removal of the metal skeleton first)?

What about via the front? How is the calculator constructed behind the metal faceplate? Is the contact/rubber dome sheets accessible once the metal faceplate is removed, or is the plastic calculator casing in the way?

And if I use the from-the-back removal technique, what are some methods for re-installing the 50 or so attachment posts?

I'd like to hear from others about their removal/repair experiences on the Pioneer calculators.



Pioneer keyboard surgery
Message #7 Posted by Randy Sloyer on 11 Dec 2002, 8:08 a.m.,
in response to message #6 by Harvey

Don't take it apart, yet...

Dust alone around the keys should not be a problem since the keyboard is reasonably sealed from dirt and dust. A canned air blaster should do the job, under no circumstances should you use compressed air as it always contains some trace amounts of oil from the compressor. This is where Pioneer keyboards are their weakest, as their resistance to liquids entering is very poor. Every one of the heat stake posts that hold the sandwich together is a conduit for liquids to enter and capillary action draws it onto the membrane circuit. If the liquid is sticky when dry, you have possibility of increased snapping. If the liquid covers the circuit traces, you'll have an intermittent or dead key. The worst case is when there is so much liquid that it bridges multiple keys as the keyboard x-y matrix is actually on the address and data bus of the Saturn cpu and the resistance of liquid is low enough to cause current flow in the CMOS circuitry resulting in a dead calculator.

As for getting gunk out of keyboards, I have adopted David Smith's process of keyboard restoration using an ultrasonic cleaner with excellent results. This involves 3 cycles of cleaning with distilled water with several days of drying time between each. This allows each new introduction of clean distilled water to wick into the keyboard and dissolve the goo. The final drying should be done in elevated temperatures, at about 120f for at least 12 hours. Put the batteries back in and give it a go, as they say.

Taking the keyboard apart should only done when all other possibilities fail. There are several ways to do this, but they are very time consuming and the outcome is not a sure thing, especially with regard to each key having the proper feel. Their is no frontal access to a Pioneer keyboard, only from the rear. Under no circumstances should you try to remove the front brown aluminum bezel. It will only get you a bent bezel and not get you any closer to a functional keyboard. There have been cases where the bezels have been successfully removed using a hair dryer and lots of patience, or solvents to soften the adhesive, but there is nothing to be gained from the frontal approach. You DO NOT need to remove the bezel to open the calculator, as Paul Brogger's article details a very good and easy way to open a unit from the back only. Once done, the only way to get to the keyboard parts is by reversing the assembly process which involves either reforming the heat stake mushrooms back to a straight pin or simply cutting them off. Then you could repair or replace. I did this once on my own 42S as I had nothing to loose as the on/off button circuit had gone open. Before taking that leap though, I would try the cleaning approach first.

I would be happy to run your unit thru my ultrasonic cleaner if you don't have access to one. Just email me, my address is on my name link.

Re: Pioneer keyboard surgery
Message #8 Posted by joe r on 15 Dec 2002, 8:35 p.m.,
in response to message #7 by Randy Sloyer

Hi - I'm replying in this thread since I'm not sure where else to put it. I'm also new to this forum, so I apologize in advance for any false presumptions on my part.

I recently came to own a 42s which was thought by the previous owner to be inoperative. After testing it out for a hew hours, I could see why: the ON/OFF (EXIT key) function does not seem to work after the unit is initially turned ON. Weird, huh?

The symptoms are as follows: with fresh batteries and a recent machine reset, the unit will turn ON, but with a longer than usual delay. Subsequently, any function will work - even the SHIFT key - with the sole exceptions of EXIT and the "9" key (MATRIX). The machine will, however, turn OFF - but only after a very long delay, and will not then turn back ON without a reset.

Has anyone seen this before? Will I be performing keyboard surgery? I appreciate any help, and thank you in advance.


Re: Pioneer keyboard surgery
Message #9 Posted by Randy Sloyer on 16 Dec 2002, 10:07 a.m.,
in response to message #8 by joe r

While I would not completely rule out a bad keyboard, based upon your description, it is most likely a bad 8k ram chip, or the worst situation, a bad cpu. This could be easily diagnosed if you have a spare 42S or 17B/17bii logic board to fit to the keyboard for testing. It is very difficult to properly diagnose without known good logic board. You can measure the resistance of the keyboard circuits to see if you have a hung or leaky key, but it is not a guarantee of functionality. I could provide a schematic of the keyboard if you decide to have a look.

If you do not have a spare logic board, I would be happy to take a look at your 42S, as I have the parts and a surface mount solder rework station.

If you decide to pop it open and have a look, please let us know how you make out.

Re: Pioneer keyboard surgery
Message #10 Posted by joe r on 16 Dec 2002, 12:55 p.m.,
in response to message #9 by Randy Sloyer

Thanks for your advice.

Well, I don't exactly have the spare parts for the testing - 17biis can be had fairly inexpensively, though, so I've actually been thinking about getting one for spare parts.

A bigger problem is opening up the case. Never having done so, I'm a bit hesitant - as you can imagine. This is where I begin to take you offer seriously - would you be able to perform the repair? More importantly, do you have a standard rate for this service?

Just asking, you understand. Feel free to email me with details. Thanks again.


Re: Pioneer keyboard surgery
Message #11 Posted by joe r. on 16 Dec 2002, 2:14 p.m.,
in response to message #8 by joe r

I should also have added - as I forgot - that my unit shows "9.00" in the x register whenever it starts, no matter the condition I leave it in during shutdown.

This is the symptom that really made me think there was a problem with the keyboard itself. But, would it necessarily jam the EXIT key?


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