Loud Clicking on a 48G+


Anyone have any advice on what to do with a key which clicks loudly when released? Only happens with the "4" key on my 48G+, the rest of the keys are fine.




I have a guess but I'm not sure I'm gonna be able to explain it correctly (maybe I'll not find the correct words).

There is a plastic sheet under the keyborad and this sheet has molded bubbles under each key. In the inner of each bubble, right in the middle, there's a conductive "circle" (like a black, carbon spot) and when a key is pressed, this conductive spot touches two conductive paths, array-type arrangement, right below it. The conductive paths are printed in a separated plastic sheet, connected to the calculator's circuitry.

I guess that the bubble under the [4] key in your calculator has some sort of irregularity or it has fissures. Each key has a small pin that slight glides over the respective bubble's surface when the key is pressed, and it glides back over the same path when the key is released. If the supposed irregularity is right over this gliding path, when the key is released the pin is forced over it and loudly clicks.

If you want to try a brief test, please slowly press the key and try to sense any irregularity or hear a soft sound. If it happens, stop pressing it and them release it slowly. You'll probably hear the loud click if it happens this way.

I cannot figure a solution out of this other than opening the keyboard, what needs opening the calculator first.

Hope this helps identifying the aggressor.

Best regards.

(Please, if someone understood, agrees with it and wants to improve the explanation with better terminology, be my guest)


Thanks Luiz for the clear explanation. I tried your suggestion of a slow press and release, and the loud click was still quite audible when I did this. But if I press on the extreme left-hand side of the key, the click goes away.

I'm not sure that I want to dismantle the calculator to fix the problem as it is still under warranty. I can live with this, but it is rather irritating. Should I return it to HP and ask for a replacement before the warranty expires?

Thanks again



About returning it to HP before warranty expires: yes! I would!

Now you add another fact: if you "shift" the key by pressing it on the extreme left hand (a small rotation because of the torque) then the pin that acts over the bubble will glide over another path, confirming our expectations. BUT the click may also come from the molded plastic.

If you have not seen an HP48 keyboard without the aluminum faceplate, imagine that each key is molded with two plastic sticks (lower face) that bond it to the case. These sticks are slightly bent each time a key is pressed. If there is loose, surplus plastic (plastic barbs) on any of them OR in the key itself, chances are this spare plastic is also causing the clicks, what is a lot harmless.

Well, I think it's a good reason to claim for a new replacement. The new 48 series (I have a new 48G+) has the same black-dots LCD found in the HP49G. A lot better reading...

Success! And let us know about this.

Luiz C. Vieira - Brazil


Chances are, you might get a replacement GX with the clicking sound under another key. See this posting:


Hi Luiz

I contacted HP, who phoned my local store and got the calculator replaced out of the store's sock this afternoon.

So I have a new 48G+. But there are differences between the calcs.

Firstly, I didn't realise it (and this was pointed out to me by HP) that even though I bought the calc. in May last year, it was actually made in 1998. The calc. I swopped it for was made in 2002. Although both were made in Indonesia, the screens and keyboards are different. The old one's screen was a blue-green colour, while the new is the "black" you refer to, and is as you say more legible.

The keyboard on the 2002 model has duller keys that are not as shiny as the 1998 model. And the lettering is not as crisp or smart. I am not sure if the lettering on the 1998 keys was moulded into the keys; the lettering on the 2002 keys is certainly printed on.

But that aside, the 2002 version's keyboard is not as noisy as the 1998. Certainly there are no "snapping" keys. That, with the improved screen more than makes up for the poorer quality of the key faces.

Thanks again for your advice. And thanks to HP for such quick service - all within the space of 2 hours.


Hi, Gray;

thank you for sharing the good news with us.

I'm sincerely glad it is fine for you, now. Also, I'm glad it is the new black-dots LCD version.

Enjoy the new one!

Best regards.

Luiz C. Vieira - Brazil

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