HP33s Keyboard Issues


I preordered an HP33s when they first came out, and got one of the early units from Samson Cables. By 11/2004 the keyboard was no longer registering clicks consistently so HP replaced my calculator with my current unit: CNA417*****.

Now my second HP33s is having keyboard troubles: the '+' key clicks but does not register if you accidentally press the left half of the key. I called HP technical support this morning to ask about a replacement, but they said they could not replace it again because it was too far out of warranty. Fair enough, but does this mean I'm going to have to replace my $50 calculator every 18 months to keep a reliable copy?

I spoke with the only other colleague at work who I am aware of having an HP33s, and her '8' key is malfunctioning. So in my limited sample size of 3 calculators, the HP33s is 0-3 on keyboards. On the other hand, the HP technical support person said the calculators in his office were all working fine. (Maybe I should have offered to trade.)

That is why I am turning to this board. I am aware of the display upgrade and the rom upgrade for the HP33s. I am also aware of a keyboard upgrade to the HP49g+. I tried doing a search on the HP33s keyboard, but was not able to find a thread referencing any issues. Am I simply having bad luck? What are other owners' experiences?

Thank you!


I also got one of the first 33s (CNA4110). Appart from draining the batteries a bit faster than I would wish, I have absolutely no keyboard problems and I take this calc to pretty rough places. I am actually at my 3rd bag...


Edited: 3 Apr 2006, 5:39 p.m.


I have two 33S calcs: one older and one new (with decimal fix) and both keypads repsond the same way. If you're used to being fast on the keypad as with previous HPs, then you're going to miss strokes on the 33S. I push the button and hear the click, but it does not register on the display. I originally had this problem on my 49G+ models but the ROM 2.00 fixed that. When I switch back and forth between my 41CX and 33S at work, I'm starting to dislike my 33S more and more because of the same problems you're experiencing with your 33S. I'm not sure if there is a fix for this and I'm 0/2 with my 33S calcs. BTW, I was 0/3 with my 12C Platinum for the exact same reasons, and 0/1 with a 17BII+. (As I mentioned, I was 0/2 with the 49G+ for the same reason before the ROM fixed it.) For comparison, I have never had this problem with any of the older HPs, and I have about 28 different models of them.


First: I have three 33s, two old display and one new CNA 52707099. All the keyboards function properly. I have missed keystrokes only because as Stephen said, we are used to the speed and square-shaped keys.

Second: Stephen, have you experienced consistent results over time since you upgrade to ROM 2.00? I am considering getting a new 49G+, but the earier one I owned had a stiff keyboard and began "freezing" while in use.



I've not been having any problems with my ROM 2.00 49G+ keypad (but really hated it prior to that upgrade).

When I was having problems with my 12CP calcs, someone from HP called me to address my problems. He mentioned that there are two kinds of button pushers: pushers and pokers. He asked what camp I was in. Since I'm used to going very fast, I said that I was a poker. Thinking about that more, I think that fast pokers are the ones having problems with most of the newer calcs. If you "push" the button, then you probably are not having problems. (If you still use an older HP, then either method is fine.)


John posted,

Now my second HP33s is having keyboard troubles: the '+' key clicks but does not register if you accidentally press the left half of the key...

I spoke with the only other colleague at work who I am aware of having an HP33s, and her '8' key is malfunctioning.

I also noticed that the '8' key on my early (CNA413xxxxx) unit would sometimes not register if the upper right corner of the key was pressed, even though they key moved and clicked. Not an intolerable problem, but that never occurred on my HP-engineered calc's.

Arnaud posted about short battery life. I just had to replace the two expensive (US$4) thin cells after two years of light service and modest use of RAM, and the continuous memory was quickly erased in the process. The 3V cells registered 2.7 V open-circuit, and the low-battery indicator had just come on.

-- KS


Karl; That memory erasure story is probably unsetteling for anyone who has a couple of k of programs into their 33s and thought ability to change one battery at a time made them safe. It's good you posted a warning but sour cheese for you, old man.


"db" --

Oh, well. I didn't lose too much programming. It's possible that I didn't follow the procedure, and removed both at the same time (guess I'm used to doing that).

The HP-33S seems to have a large continuous-memory capacitor. I removed both fresh cells, and was still able to turn the calc on with the stack contents unchanged! After reinstalling the cells and turning it on, the low-battery indicator displayed for several seconds, then disappeared, perhaps indicating a recharged cap and full voltage.

The design is reasonable, but I suspect that the charge capacity [mAh] of these thin CR2032 cells compares unfavorably with that of the 13/44/76/357 button cells used by Pioneers and Voyagers.

-- KS


Hi, Karl:

Karl posted:

" I suspect that the charge capacity [mAh] of these thin CR2032 cells compares unfavorably with that of the 13/44/76/357 button cells
used by Pioneers and Voyagers."

    I've done no extensive research whatsoever and you're probably quite right, but in my experience, the two CR2032 cells that do power my heavily-used SHARP PC-1350 do last quite long, despite the LCD graphics display being quite big and the CPU running quite fast for a vintage handheld. They'll typically last a whole year, with pretty intensive daily use (long-running 'challenge-style' programs, etc).
Best regards from V.

Thank you to everyone who responded! The feedback has been very helpful and informative. It's nice to know that I do not have an isolated problem.

Sounds like at least part of the issue is that I'm spoiled by my experience with older HP's. Apparently I am a "fast poker". Since I don't look at my calculator when I'm using it, because it's faster that way--like touch-typing, the keyboard missed strokes mean I get garbage at the end of many calculations.

Looks like I will have to do some shopping around to find a keyboard that works as well as the old HP's. Thanks again!


I'm going to tell you my experience:

one month ago I bought a brand new HP 33S from an Italian HP Store. I immediately realized that the 0 keypad (which holds INPUT and VIEW commands too) could be used only if you pressed the upper left corner. Pressing in the middle was a bet: one fourth of the keypresses was right. Imagine to digit 1000000!

I ask the store what to do: they replied that they would change the machine with another one (in EU there are two years of warranty), but in the meantime, they asked if I could do the following: grab the key with two fingernails and shake it left to right, to see if the little pad under the key would set up. Of course, this didn't work, so now I have another HP 33S, which work perfectly, apart the ex key (holding 10x and integration too) which manifests the same problem, but this time it works if you *don't* press only the upper left corner. This is a nuisance rather than an issue, so I can cope with it.

Hope this will help someone.

-- Antonio

Edited: 14 Apr 2006, 5:20 a.m. after one or more responses were posted


Quo vadis HP?

This all sounds worse than the stories about TI-keyboards in their worst days in the early eighties. Malfunction for a near out of the box calculator is just ridiculous.


I have an HP33s with serial number CNA5020...., and it has a perfectly working keyboard with good tactile feel, and also has the problem with the decimal fixed. I am quite pleased with it and use it daily at work. I have 2 older HP33S, serial number CNA4.... that do have the problems you describe with the keyboard. One is a replacement unit from HP. My older units are therefore unreliable and I never use them. I bought another new unit, serial number CNA52...., and it seems to have a good keyboard that responds even when you hit the key off-center.

I think that units with serial numbers CNA5.... and later seem to have revised keyboards that are more reliable. The older units are still on the shelves however, and you have to be careful regarding what you are actually buying.

Good luck

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