12C has keyboard problems, too


It looks like it's not just the 15C LE that has problems with keys in the keyboard not working properly. I just grabbed a brand new 12C (just opened the packaging, serial number 4CY1300M4V), and its [PV] key doesn't register unless you press it really hard.

Anyone else seeing problems with recent 12C keyboards, too?



Eric, here is my experience with HP-12C keyboards:
Purchased a 12C from a local electronics store in Santa Clara about 5 months ago which had a defective ENTER key, went back to replaced it with another one and checked the new one in front of the customer service which was also defective. We went through ALL 6 units in the store (Brand New) which had defective keyboards, 2X ENTER Key, PV, PMT, 5, +. So I drove to another store in San Jose which had 7 in stock. ALL HP-12C's except one had issues with Keyboard. 12 Bad ones and one good one, 8% Yield. Also my 30th Anniversary 12C (from HP EPP store) has a bad sigma and + key but too frustrated with HP to replace it. No more new HP calculators unless I can test the keyboard before I purchase it.

Edited: 10 Feb 2012, 1:40 a.m.


Some 5 months ago, I got a 12c+ from you (4CY11705LP). Bad ENTER key, bad "1" key, unsatisfying keyboard overall.

In another thread on this forum, some three months ago, we seem to have reached the empirical conclusion that calculators from 4CY have lower quality keyboards than calculators from the other factory (CNA). They can easily be recognized by a slightly different key font, and, notably, by the uncommonly large "%" key sign see here and here .

In my case, after many contacts and much frustration with an incredibly inefficient HP costumer service (Brasil), I decided to open the calculator. It turns out that the circuit board was not sufficiently pressed down by the heat stakes. I thus introduced a felt pad on the "bad key" region, so that the back panel would slightly push the board down. Both keys are now working fine. It still is an overall lower quality keyboard, though :-(

The 15 LEs seem to be produced only on the CNA factory. That is probably why the general feel of their keyboard is always good. But, as we all know, problems with particular keys exist there, also.


Edited: 10 Feb 2012, 3:54 a.m.


Of my recent production HPs, only one has keyboard issues, and that's actually a 30b.

  • 12C - 4CY fine
  • 35S - CNA fine
  • 15C LE - CNA fine
  • 30b - 4CY fine
  • 30b - 4CY inconsistent ) key

Maybe there really is a rhyme/reason to this, but it seems to me like common low-cost, average reliability Chinese manufacture.

In my experience, HP has been on par or better than their peers in this area.


I opened up one of the defective units with defective PMT and PV keys, no click, hard to press and difficult to respond. Removed the heat stakes holding the keyboard and found out that there is rubber pad between the keyboard and the keypad.

HOWEVER the rubber pad was almost 1/4"-1/2" bigger than its intended space so in order to fit the pad, it was wrinkled and somewhat folded into the space between the keyboard and the keypad. The keys over the folded/wrinkled areas of the pad failed to work properly thus required more force to press and didn't click. I was able to cut strips of that rubber pad in order to reduce the size to fit and put the keyboard back on using small screws. All keys worked fine. I am not sure all the problems on HP-12C keyboard were caused by this issue but at least one was.


So far no issues with my 30th 12C. Serial number starts with CNA. Also have three 15C LEs with CNA serial numbers and no keyboard issues. Maybe the 4CY plant?


Yes, I have bought a new HP-12C with serial 4CYxxxx and the 1 key and 9 key have to be pressed very hard to be recognized.

The calculator is basically unusable in this condition.

I have contacted HP support and wait for an answer.
Hopefully they will replace it.

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