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:

  • 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: 19.04.30

  1. On 17-Oct-2019, Anonymous wrote: 
    how to remove or open the battery door to replace battery in hp 12c calculator
    Your reply to Anonymous
    • On 21-Oct-2019, Peter Tong replied: 
      there is a battery cover at the back of the 12c. Just slight it out the cover then pry the coin battery out with a paper clip and replace it with a new battery.
      Your reply to Peter Tong

  2. On 07-May-2019, Kath wrote: 
    ‘Pr Error ‘keeps showing on the display of my hp12C and I can't get rid of it. I have tried all the test . But it still doesn’t go off . What should I do ?
    Your reply to Kath

  3. 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

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

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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

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