Question about HP 12c Calculator

1 Answer

12c Hp Financial Calculator. The problem is:- depressing the number 1 key does not register on the screen. All others do. The number one key sounds and feels the same as all the other keys

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  • andrew_stirl May 25, 2011


    The procedures you set out have not worked.

    A damaged key pad seems unlikely as the calculator sits on my desk at all times..Not taken anywhere.

    Are there any other suggestions??

  • andrew_stirl May 25, 2011

    Thanks Jas



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  • Master
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Welcome to FixYa!

The flexible metal switch pad under the key pad number 1 is most likely broken. You can only tell if number 1 does not respond. The sound and feel of a defective key pad will not differ than the other keys as the metal switch pad is very flexible and blends well with the rubber key pad.

However, you can do 2 types of resets just to make sure that the problem is with the metal switch pad under the key pad. The resets will clear the memory of the calculator and would restore your calculator in to it's factory setting thereby removing any key errors in the process.

Note: Resetting the calculator will erase any stored data.

Resetting the calculator using the keypad
The easiest reset is done from the keyboard. To reset the calculator, follow the procedures below in the order presented.

Press ON to turn off the calculator.
Press and hold [ - ] .
Press and release ON .
Release [ - ] .
The screen will display "Pr Error "
The calculator will reset to the default settings, and the memory will be erased.

If the above reset did not restore the calculator to normal, continue to the next section.

Resetting to drain the capacitor
If the calculator is still performing unexplained errors or will not turn on, it might have a static charge. This means the capacitor is full. The previous reset will not drain the capacitor. With this calculator, there are two options for draining the capacitor. The option to use is dependent upon the serial number of the calculator to be reset. The first option is a paperclip reset.

Paperclip reset
A paperclip reset can be performed on all HP 12C calculators with serial numbers before CN11500001. This will include serial numbers that start with numbers or with other letters. These calculators will have three 1.5 volt button cell batteries. Follow these steps for calculators in this serial number range:

Remove the battery door.
Take the batteries out.
Take a paper clip and bend it out enough to cross over from one terminal to the other.
Hold the paper clip across the battery terminals for approximately ten seconds.
Replace with a fresh set of batteries, being sure to follow the polarity assigned. Note the picture beside the battery cover.
Replace battery door.
Turn on the calculator. The display should read "Pr Error". Press and release the ON key twice.

Coin reset
A coin reset can be performed on all HP 12C calculators with serial numbers after CN11500001. These calculators will have one CR2032 battery.

Remove the battery door.
Tap the calculator gently into your palm to remove the battery.
Place a small battery-sized coin (penny or a dime US) flat into the battery compartment. Hold the coin in place with your finger.
While holding the coin, turn the calculator over, press the ON key, and hold for 10 seconds.
Remove the coin.
Replace the battery, being sure to follow the polarity assigned. Note the picture on the calculator.
Replace the battery door.
Turn on the calculator. The Display should read "Pr Error ". Press and release ON twice.

Other solutions
If the calculator did not display the "Pr Error " message after resetting, or it did not correct the error, then remove the batteries for 24 hours.

NOTE: The batteries must be removed for at least 24 hours to drain the capacitor completely.
After letting the calculator sit without batteries for at least 24 hours, replace with fresh batteries.

If the solutions above did not correct the problem, then you need to service the calculator for the metal switch pad to be replaced.

Thank you for using FixYa.
Have a great day,

Posted on May 25, 2011

  • Jas Barinaga
    Jas Barinaga May 25, 2011

    Hi Andrew,

    As much as I want to help you, that is all I can suggest. Reset can fix all possible errors except for hardware errors/malfunction such as visible hardware parts inside and out, chips, capacitors, transistors, lcd, switch pads, battery problems, main board, etc.



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The following problem is not difficult, however, I am having trouble calculating the answer using my HP 12c Platinum. Can you please provide a step by step explantation of how to calculate the answer to...

1. Make sure the HP-12C is in compounding mode. Press STO-EEX repeatedly until a tiny "C" appears in lower right of display.
2. Make sure "BEGIN" is NOT shown in the display. If it is, press g-END.
3. Clear financial registers: f-FIN. (That is really the "f" key then kind of the "Clear FIN" key -- I'm sure you'll see it.)
4. Enter zero as "initial investment". CLx, then g-CF0. (You have to do this because the 12C actually computes the "NPV" as an excess or deficit over the entered "initial investment". By entering zero, you force the calculator to just give you the actual net present value.)
5. Your first cash flow is +2.00. So, enter 2.00, then press g-CFj.
6. Next cash flow: +2.10. Enter 2.1, then press g-CFj.
7. Last cash flow: +22.20 (the final value of the stock plus the last dividend payment). Enter 22.20, then press g-CFj.
8. Enter the 10% interest (a.k.a. discount) rate. Enter 10, then press "i".
9. Compute the NPV. Press g-NPV. The answer is indeed 20.23 (at least to two decimal places).

Apr 08, 2014 | HP 12C Platinum Basic Calculator

1 Answer

HP12c seems to not have enough room for numbers BEFORE the decimal point. I try to enter the number "85" and all that will show up is the 8.000000000

Initial Setup

One adjustment is important before we get started. By default the 12C displays only two decimal places. This is not enough. Personally, I like to see five decimal places, but you may prefer some other number. To change the display, press "F" and then the number of decimal places you wish to display. I would press "F 5 " to display 5 decimal places. That's it, the calculator is ready to go.
You need to hold the "F" key.---------

    1. Press and release the gold PREFIX key (f).
    2. Press the number key for the desired number of decimal places (0 through 9).
------------ Click this link below and follow the procedure:---
----------- This should help.Thanks.Helpmech.

Jul 21, 2011 | HP 12c Calculator

1 Answer

PV=$40,000;I/YR=3.3;N=40;SOLVE FOR FV

If necessary, press f [FIN] to clear the financial registers.
4 0 0 0 0 PV ( enter present value )
3 . 3 i ( enter interest rate )
4 0 N ( enter number of periods)
FV ( compute future value )

Apr 19, 2011 | HP 12c Calculator

1 Answer

My hp is on RPN setting, and is set to two decimal places. As an example of the problem, when I key in '45' and press 'ENTER' the screen shows '45.' When I then key '2' and press '+', before I can press...

According to your problem, I think your calculator needs master reset.
May be the keys attached with each other and make malfunction, check
it. Also may be software problem. rush to the nearest HP service
center or can contact by visiting website.

Apr 18, 2011 | HP 12c Calculator

1 Answer

Do you have advice in calculator choice between HP 12 c and the TI BA II Plus Professional Financial Calculator? Assuming that I get proficient with RPN (which I'm learning now); is one faster than the...

The 12C is more expensive and more powerful than the BAII+Pro. The HP is also programmable, which the TI isn't. Starting from scratch (assuming you've never used a calculator before---a somewhat unreasonable assumption) the TI might be easier to learn, at least initially. But after a certain point, the HP will leave the TI behind. The HP is faster and more capable.

There are at least three different versions of the 12C available. There's the original 12C, the 12C Platinum, and the current 12C. The only way to tell the difference between the two non-Platinums is to look at the battery compartment---the original uses three button cells while the newer uses two coin cells. The newer one is MUCH faster. The Platinum, however, can use RPN or algebraic.

Unless your choice is limited to the 12C or the BAII (by the requirement of an exam, perhaps), you might want to look at the HP 20B and the HP 30B. Programmability aside, they're even more powerful and easier to use and faster than the 12C, and the 30B is also programmable.

There are other considerations, of course. Factors such as the feel of the keyboard, the 12C's landscape orientation as opposed to the others' portrait orientation, etc, are all matters of personal preference.

Disclaimer: I own multiple HP and multiple TI calculators. I tend to use HP calculators for calculating, while I use TI calculators to answer questions here at FixYa.

Mar 23, 2011 | HP 12c Calculator

1 Answer

Hi, I have an HP12C and for some reason the

Turn the calculator off. Hold down the period (decimal) key and hit the "ON" button at the same time.

Mar 03, 2010 | HP 12c Calculator

1 Answer

Has new battery and wont turn on

Hello, You can try to perform the self-test. Procedure is as follows. To perform the self test on units with two batteries:
  1. Turn the calculator off.
  2. Press and hold the c01788482.jpg and c01774569.jpg keys; keep both keys held down for the next step.
  3. Press the c01788481.jpg key so the c01788483.jpg and c01788481.jpg keys are held down simultaneously.
  4. Release the c01788481.jpg key.
  5. Release the c01788482.jpg key, followed by the c01774569.jpg key. The main test screen displays the following: '1.L 2.C 3.H'.
    • Press c01788484.jpg to perform the LCD test (all LCD segments will be turned on). Press any key to exit.
    • Press c01788485.jpg to perform the checksum test and see the copyright messages. Press any key to go from one screen to the next until the main test screen, '1.L 2.C 3.H', is displayed again.
    • Press c01788486.jpg to perform the keyboard test. Press EVERY key on the keyboard until all the keys have been pressed at least once. The screen will progressively turn off with each key press. Once all the keys have been pressed and the screen is clear, press any key to return to the test screen.
Press c01788481.jpg to exit the test system. This will also turn the calculator off. If the calculator detects an error at any point, it will display an error message. For the HP 12c financial calculators with one battery, to perform the LCD self test:
  1. Turn the calculator off.
  2. Press and hold the c01788480.jpg key, and simultaneously press and hold the c01788481.jpg key.
  3. Release c01788481.jpg then c01788480.jpg .
  4. After a few moments, all elements of the screen should be displayed. Press any key to exit.

Nov 02, 2009 | HP 12c Calculator

1 Answer

I just replaced the batteries in my HP 12C calculator and when I turned it back on the display looks like this 0,000. How do I get the display to show decimals instead of a comma?

Here is what the manual for the HP 12C Platimum financial calculator says on page 17 of 275

Digit Separators
As a number is keyed in, each group of three digits to the left of the decimal point is automatically separated in the display. When the calculator is first turned on after coming from the factory — or after Continuous Memory is reset — the decimal point in displayed numbers is a dot, and the separator between each group of three digits is a comma. If you wish, you can set the calculator to display a comma for the decimal point and a dot for the three-digit separator. To do so,
turn the calculator off, then press and hold down the [ . ] key while you press [ON] Doing so again sets the calculator to use the original digit separators in the display.

Hope it helps.

Oct 06, 2009 | HP 12c Calculator

1 Answer

How can i tell the difference b/w hp12c and hp12p. i bought a hp12p from ebay(it's a stupid decision, I know!) and when i solving for IRR, i felt its running quite slow. I think the guy sold me the hp12P...

I couldn't find any reference to a HP calculator model 12p.
There is a HP 12c financial calculator and a 12c Platinum financial calculator.
Check both models (for images, specifications, functions, user guides, etc.) :
HP 12c Financial Calculator
HP 12c Platinum Financial Calculator

Aug 06, 2009 | HP 12c Calculator

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