A few different problems may cause your Sharp calculator to malfunction or stop working altogether. Fortunately, these issues are apt to be minor, and you can make a quick repair at home with only a small screwdriver and a ballpoint pen. For instance, when the calculator display is dim, the contrast is poor or the readout is blank when you turn on the device, it may be indicative of a dead battery, which is a simple fix. Other minor repairs may be needed to clear bugs in the calculator's programming code or to restore non-responsive keys to working order.
Turn off the calculator. Using a screwdriver, remove the two screws on the back of the calculator securing the battery compartment cover.
Slide the battery cover up and then lift to remove it from the back of the calculator. Pry the battery loose with the tip of a ballpoint pen and remove it.
Insert a fresh battery with the "+" sign facing up. Close the battery cover and fasten the screws you removed earlier.
Press the reset switch located in the small hole on the back of the calculator by inserting the tip of a ballpoint pen into the hole and pushing in.
Hold the reset switch for three seconds and then release it to reset your calculator. This will clear all data stored in the calculator's memory and reset the device to its factory defaults. This should bring non-responsive keys back to life and clear any program glitches that might have been causing the calculator to malfunction.
Turn on the calculator. Adjust the display contrast by pressing the "2ndF" button. Press the "SET UP" button and then press "3." Use the "+" and "-" buttons to adjust the contrast until you can easily read the display. When the settings are correct, "Normal Mode" should display on the calculator. If this message does not appear, try removing and re-installing the battery and repeating the procedure to reset the calculator.
Things You'll Need
If the keys still don't work after performing these troubleshooting steps, you'll need to take your calculator a Sharp service facility.
Keep a written record or use a PC-Link to save important data on the calculator to your computer before you begin these repair procedures. Removing the battery and resetting the device to its default settings may permanently erase your data.