Press [ON] [PMT] at the same time.

It should show ’ 1 5crEEn ’ on the display.

Press [+] to move down the list.

1 Screen

2 Keyboard

3 Checksum

4 battery

5 version

6 copyright

7 test sys

8 Slow clk

Stop at the respective option and press [=].

1 Screen -lights up all segments, icons, display

2 Keyboard - at the end of the test, yields ‘Good’

3 Checksum - yields 244.244  Basically the numbers before and after should match (one is the calculated number, the other is the number put in the flash to compare against). Note: some variant may yield 118.118 or 96.096, these are good too.

4 battery - 3.500

5 version - 7-13-2010

6 copyright - HP 2010 then 1,752

7 test sys - pressing = turns test sys off

8 Slow clk (clock?) SC -28,500.00

If you suspect the calculator is giving a wrong answer, it could be TVM compounding settings.  HP 10bII+ is factory set to assume monthly compounding (12/Yr). To follow some examples, you may need to set annual compounding (1/Yr).  You can set it here  or another slightly more detailed writeup here.

If you still not getting the desired answer, you could try resetting your HP 10bII+ calculator.