Casio FX-890P Owner's Manual page 14

Note: This hardware test will erase all programs and data stored in the unit.
Selecting one of the options of the self-test menu will allow following tests
0. Test of the Read Only Memory, computing check sum and XOR check
1. Test of the symbol displays, outside pixels, uneven pixels, even pixels, all
pixels together. Go from one test to another with the .
2. Test of each key, starting with MENU and finishing with . . The computer
will ask to depress each key, notifying a successful result with the beeper.
3. Low Battery test. This allows testing the main battery and backup (SUB)
battery status. Press BRK key to go back to the SYSTEM* menu.
4. Test of the Random Access Memory. This test will return the amount of RAM
in the unit (main and optional extension pack) and test it by writing and
reading it, returning "CHECK OK" when successful. Press any key to go back
to SYSTEM* menu.
5. Writing test of the RAM. This is the first phase of the [4]RAM test.
6. Reading test of the RAM. This is the second phase of the [4]RAM test, and it
will work properly only if executed just after the writing test. Use the BRK key
to exit the test in case of an error.
7. Rest of the display and the beeper. Press the BRK key to go back to
SYSTEM* menu.
8. Test of the 3-pin connector.
9. Test of the display using a loop printing the character set. Exit the loop with
the BRK key.
+ Test of the Input / output port.
Exit the SYSTEM* menu by pressing the CAL key.
14
. key.