Casio fx-85ES (Natural Display)
The Casio fx-85ES is a scientific calculator with 10 digits precision and formula input logic. It has 249 functions, 50 keys, and an LCD (liquid crystal) display. The power source is Solar + LR44. The calculator was manufactured in China. Functionally the fx-85ES is the same as fx-83ES with solar power.
Facts at a glance:
|Power Source||Solar + LR44|
Note that diagnostic tests generally delete any data on the calculator. Be sure to back up any important information held in the calculator before running these tests.
While holding SHIFT and 7 keys (or just SHIFT key for early models) press the ON key. Pressing the SHIFT key shows 5 display test patterns in turn, followed by the ROM version. Press AC to get the contrast test screen, and press AC again to get to the keypad test - the numbers then increase as each key is pressed in the correct order (omitting the ON key which exits test mode).
If you have a Casio fx-85ES that is no longer working, you can consider replacing the calculator with a modern equivalent. We suggest the following current model as a replacement: