Tutorial for Users » hp 12c (platinum) - Resetting the Calculator

Calculator Resetting

Sometimes a calculator will lock up or will not respond correctly. The calculator may require a reset for a variety of reasons. These resets will erase the memory on the calculator and restore the calculator’s defaults. For this reason, it is important to back up any critical data.

The easiest reset is done from the keyboard. To reset the hp 12c (HP12C) or hp 12c Platinum 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"
  • Press {Enter} and 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.

If the HP12C 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.

A paperclip reset can be performed on all HP 12C calculators. These calculators will have three 1.5 volt button cell batteries. Follow these steps for calculators in this serial number range:

  • Remove HP12C 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 HP12C calculator. The display should read "Pr Error". Press and release the ON key twice.

Updated On: 12.09.20

  1. On 12-Oct-2018, Mike wrote: 
    My display when turning on is 0.0000000000 with a "BEGIN" in center under numbers and a "C" on right side under numbers
    Your reply to Mike
    • On 12-Oct-2018, Anonymous replied: 
      Hi Mike. Try pressing [f] 2 this will shift the decimal place to 2 digits.
      Your reply to Anonymous

  2. On 15-May-2018, Aoril wrote: 
    Begin shows on my screen. How do I clear the begin?
    Your reply to Aoril

  3. On 04-May-2018, Mufason wrote: 
    How do I turn off the rpn on the screen
    Your reply to Mufason

  4. On 18-Jan-2018, Harvey wrote: 
    when I try to do a basic math problem like addition and I enter the first number then hit the function key it comes up with 0.00 so it won't let me put in the next number and have it solve?
    Your reply to Harvey

  5. On 19-Nov-2017, Loprophile wrote: 
    Pr Error keeps showing on the display can't get rid of it. What will I do
    Your reply to Loprophile

  6. On 05-Nov-2016, Aba wrote: 
    do not work proveerle the Enter, keep showing the news numbers I put and not multiplies
    Your reply to Aba

  7. On 11-Sep-2016, Will wrote: 
    I have an L' in the seventh position of my display and I cannot get it to go away. All functions work otherwise but L' remains in the display and interrupts the sequence of the numeric result. I've tried all methods to reset the unit to no avail. Any help is appreciated.
    Your reply to Will

  8. On 28-Feb-2016, OA wrote: 
    My "0" key and "." key don't seem to work anymore. The keys aren't stuck. I press them and it seems to be working fine, but nothing happens on the display. It's almost like the keys got disconnected somehow. I trie resetting the calculator, but no luck. Has anyone else had is issue?
    Your reply to OA

  9. On 08-Jan-2016, Bern wrote: 
    Help. My HP 12c Platinum ENTER key requires a long and hard press to work. Anyone with an idea of how I can resolve this? I have tried all the reset methods and they didn't seem to work.
    Your reply to Bern
    • On 08-Jan-2016, Ron replied: 
      Take out the batteries and install fresh ones. If this doesn't help, you may have worn out your Enter key (unheard of for the older Hp 12c). The Platinum version is a relatively newer Hp 12c with a less robust (cheaper) keypad than the earlier and older Hp 12c. Any Hp 12c made within the last decade is NOT any better. Today's Hp calculator is made to last 5-10 years, not 10-20 as their earlier calculators.
      .
      The Hp Prime seems to be an exception. However, that is a current high end graphing calculator.
      Your reply to Ron

  10. On 22-Nov-2015, Lin wrote: 
    Help! How do I clear off the pr error on hp 12c calculator? It just appear whenever I on it. New to this Caculator so not sure if it normal.
    Your reply to Lin

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