Reviews about loose keys: Is it really that bad?


In the reviews of recent HP calculators, it is often mentioned that keys get loose and don't register, so numbers you type might miss some digits etc...

I'm wondering: is it really that bad, or are the reviews exaggerated?

I've got this old Ti calculator with rubbery keys. These keys are annoying and mushy compared to the nice clicky keys of several HP calculators. However, after 6 years of spending in a secondary school backpack and heavy use, and living on many years after that, the keys of this Ti still work and register every press.

So this Ti definitely has very cheap keys. But they don't break or get loose.

So is it really true that HP has managed to make keys that are even worse than this Ti, and break after just a few months, on its recent models?



Only in Belgium.


Is there something wrong with my post? I didn't want to troll in any case. Please let me know how I can improve my posts and I'll take it into account. Thanks.


To me, your post looks perfectly ok. I don't understand Michael's humor. ?-(

Back to the key question: The mechanics of the very first HP calculator keys are quite sophisticated, say expensive. With a retail price of several 100 dollars this is no problem. When prices dropped, cheaper mechanics needed to replace the former key construction. HP has managed (at least to some extent) to preserve the typical feel of the keys but in some cases not the durability. I've a 71B with a sunk key. It still works but there must be something broken inside.

TI and other manufacturers have had a similar problem. The keyboards of the SR-50(A) and its twins were quite good. The step to the cheap TI-30 construction (carried over to the high end TI-59) was a disaster. Bouncing keys everywhere. :-( They learned their lesson and switched to the mushy but reliable rubber dome technique. The keys are quite reliable but the feeling is a bit less pleasing then it could be.


it is the neoprene membrane between the key and the snap dome that got a hole in it and that is why the key is sunk.

I opened mine and de-staked keyboard from case, turned rubber membrane over (it is slightly asymmetric, so now the key hits a slightly different place on the membrane and all keys are fine now), then re-staked the keyboard.

You can only do this once, though, if you don't want to reconstruct the heat stakes.



Vladan, thanks for the tip. I'll leave it untouched for the time being except when more keys start to sink in.


I don't have the most recent HP10bii+, but I think people have said that its keys are fine. I do have a 30b and 12c+ from the last two years, and those keys are great.


Lode, I have trouble with the 35s recognizing keystrokes if I try to press the keys too quickly. Slowing down improves the accuracy.




I believe that is due to the keyboard processing routines in the internals of the unit, and not the keyboard itself.

As far as I know, the 35s keyboard really does not miss keys, but if you press them VERY VERY fast, it appears the scanning routines can miss a keystroke.

And, that is a somewhat educated guess on my part.


I don't seem to have any problems at all with the 35s keys. I can press them as fast as humanly possible and they all register. The only minor issue is that the "+" key makes a different sound than all the other keys...


I believe that is due to the keyboard processing routines in the internals of the unit, and not the keyboard itself.
I thought the same. But after about one year of moderate use, the Arrow-Up key failed to register reliably. You hear the click, but got a response only after pressing slightly harder. As other keys are ok, probably this is due to the strange arrangement of the curser keys and the fact that they aren't hinged.

Much more of a desaster is my 20b, on which all keys need a firm press to register.

Hopefully other HP calculators do better.


Thomas, it would be interesting to see if the keyboard of your 20b becomes more responsive with the 34S firmware. If yes, the HP firmware may be part of the problem.


I installed it once, but haven't noticed any improvements on this. It's probably about *how* the keys are pressed. There's no guidance, and it literally feels like balancing the keytop on this rubber dome when touching any 20b key.

Anyway, the 20b doesn't have a good concept mechanically at all. Function follows form. Looks great, works terribly. And that's really sad, since it is small and has an excellent LCD. A 30b without the extremely bevelled edges would have been a good thing, imo.


Yep, the keys on the 10bii+ are quite nice. No missed keystrokes, and all have nice "click" with just the right amount of force needed to activate. But I slightly prefer the keys on the 12C+ with their higher profile and longer travel.


I have the 10bII in that shape (i.e. the second version), and find it quite nice. The keys are a bit lower than the 12C & 12C+, but still good none the less. Apparently it is the fisrt 10bII (brown model) that is quite bad - but I do not have personal experience of that.


I have used many of the recent HP calculators including the 12C+, 12CP, 14Bii, 35S, 20B, 30B, and all the graphing calcs and so far the only one I have had problems with is the 20B which has a mushy key feel and does not always register for me.

To add a disclaimer... I have not used any of these machines the way I used (and still use) my HP-41 and so long term reliability is still an unknown for me.



So is it really true that HP has managed to make keys that are even worse than this Ti...

Some series of HP-48s have entire rows of keys failing (I also have one of those...), something that I have never seen in any other brand of calculators. The reason however lies not in the keys themselves, but in the poor connection between the keyboard and the main PCB. The construction of the calculator makes it very difficult or almost impossible to repair this simple fault.



A long time ago I read an article on how to fix this problem. You can actually take the 48 apart without destroying anything. The pressure pad under the zebra connector is the problem.I have one machine with this problem. If I press on the faceplate, above the F button, it works perfectly.

I also heard from someone else that merely taking the batteries out and soaking in distilled water, then drying for a week under a fan, will do the trick. Doesn't sound permanent though. I haven't been able to find either of these old posts or writings and I am too impatient to care (and have too many 48 machines that work fine anyway).

Problems with the 35s keys not registering were quite different from the old "TI-itis" of the 1970s. Problems with the 1st batch of the 49G+ were mechanical in nature and were remediated by a key-rubbing process, though a warranty replacement was offered if I remember correctly. HP changed them to work better and then made the 50G and that apparently made the problem go away completely. I don't have a 50G and never even held one in my hand.


I think that the real low point was the HP-49G+, released in 2003. At the time this was the highest of HP's high-end calculators, with sophisticated software and expandability. However its keyboard felt and sounded like a cheap toy and was equally (un)reliable. The machine was unusable. Since then HP has released the HP-50g, with similar features and (in my view) an entirely satisfactory keyboard. If it's this machine you are thinking of buying, you'll have no problems. The same is true for most recent machines (the HP-20b and the HP-35s are the only two with question marks over them so far as I know, and my HP-20b works fine).

I don't understand the comment about Belgium either!

Nigel (UK)


See my take on the 12C Platinum with silver keyboard..
I also have the 25th anniversary edition and the black keyboard version, the keys are much better on those.

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