HP 12c Platinum Calculator

[Pilgrum]

In the past this solution has worked for me.

HP 12c Calculator - Resetting the Calculator: "A coin reset can be performed on all HP 12C calculators with serial numbers after CN11500001. These calculators will have one CR2032 battery.

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

 

[Terrel L. Shields]

You might try using a can of air and blowing out the keypad...could be a speck of dirt or something stuck under the key

 

[prasercat]

Interesting. I have the same calculator, it is really nice and I keep it as a back up. I don't think I can contribute anything additional that hasn't already been mentioned.

However, I have always used the HP 17BII as my work-horse, perhaps because it has a design and functionality that represents more of a hybrid between the "business calculator" and a "scientific calculator". While I don't believe there is anything I can't do with one that I can't do with the other, I can just perform calculations much faster with the 17BII than I can the 12C, since I used a scientific calculator most of my life in the past and always at university (Although I did learn to use a slide rule for 1 year early in my university experience; however, the next year the Texas Instruments calculator made them obsolete - sheesh, just when I was really liking the slide rule!).

Naturally, the button most used will normally fail first, which would be the enter key. I really like to know the solution to this problem should I encounter it myself. Hopefully, besides sending it back in the company for a refurbishment.