Things to try before sending a calculator for service
For models 14B 17B 17Bii 21S 22S 27S 32S 32Sii 42S
This also applies to the 10C,11C,12C,15C and 16C
I changed my batteries and now my calculator is dead!
The models listed above all share the same battery size and type. The three small coin cell batteries will last a minimum of a year or more, depending upon the model. One common problem is after installing new batteries, the calculator appears dead and will not power up. This can be fixed by completely resetting the calculator. Unfortunately it will also clear any programs and variables that may be stored on the unit but once it has locked up, resetting is the only way to wake it up. Here's how:
Remove the battery cover and shake the batteries out with a few sharp smacks against the palm of your hand. Now, using a small coin (dimes and pennies work best), slip the sides of the coin between the battery spring clips so that you touch both sides of the battery clips at the same time with the coin. This discharges the internal storage and will clear memory. Now, reinstall the batteries, observing the proper polarity picture shown on the case, slip on the battery cover and turn it on. You should see a "Memory Clear", "Pr Error" or similar message and you're back to calculating.