Epson Apex 20020 - Manual (Page 174)

If all the keys function, but the characters displayed do not
match the keys, press Y and then Enter. Then re-select the
keyboard test from the DEVICE LIST, and check that you
selected the correct keyboard layout. You can find diagrams of
all the international keyboard layouts in the MS-DOS
Reference Manual.
If any key is incorrect, press
N
and
Enter.
Make a copy of the
error code and message, or print them out, and contact your
Customer Care Center.
Monochrome Display Adapter and CRT Check
Use this option to check the operation of a monochrome
display adapter and monitor. This test includes several checks
that allow you to identify particular problems related to the
monochrome display. To run this check, the color/mono
switches on the front and back panels must be set correctly for
a monochrome monitor.
You can select the individual checks from this menu:
MONOCHROME ADAPTER AND CRT CHECK MENU
1
- Monochrome
adapter check
2 - Attribute check
3 - Character set check
4 - Video check
5 - Sync check
6 - Run all above checks
0 - Exit
Enter selection number:
If you run the monochrome adapter check multiple times,
this menu of-checks does not appear and only the first test
(option 1) is performed.