Question about HP 12c Calculator

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HP12c I replaced batteries after the HP went dead. Upon restart I get the letter L with a small c underneath. Cannot turn the calculator on or off the only choice is to remove the batteries, batteries were in the proper way. Any suggestions?

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Hi jmccann656,

If you're having hard time turning on the calculator, it might caused by some changes on its setting. The best way to resolve this issue is by doing a calculator resetting. Please take note that resets will erase the memory on the calculator and restore the calculator's defaults. I recommend to back up any critical data before performing the reset. To reset the hp 12c (HP12C) calculator, follow the procedures below.

1. Press ON to turn off the calculator.

2. Press and hold { - }.

3. Press and release ON.

4. Release { - }.

5. The screen will display "Pr Error"

6. Press {Enter} and the calculator will reset to the default settings, and the memory will be erased.

If the HP12C calculator wont turn on and still performing unexplained errors , 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:

1. Remove HP12C the battery door.

2. Take the batteries out.

3. Take a paper clip and bend it out enough to cross over from one terminal to the other.

4. Hold the paper clip across the battery terminals for approximately ten seconds.

5. Replace with a fresh set of batteries, being sure to follow the polarity assigned. Note the picture beside the battery cover.

6. Replace battery door.

7. Turn on the HP12C calculator. The display should read "Pr Error". Press and release the ON key twice.

Hope it helps.

Thank you for using FixYa.

Posted on Mar 25, 2011


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