Epson 20 - Manual (Page 156)

Run All Above Checks
To run all the tests on the menu in sequence, press 6 and Enter.
When you choose this option, all checks for the monochrome adapter
and CRT are performed automatically in sequential order. Although
you do not start each test, you must still supply the appropriate
responses to progress from one test to the next. Press any key to
return to the menu.
Color Graphics Adapter and CRT Check
Use this option to check the operation of a color graphics adapter (or
EGA or VGA) and display. This test includes several checks that
allow you to identify particular problems related to the color display.
To run this check, the monitor switch on the front panel must be set
for a color monitor.
You can select the individual checks from this menu:
COLOR GRAPHICS ADAPTER AND CRT CHECK MENU
1 - Color graphics adapter check
- Attribute check
- Character set check
4 - 40-column character set check
5 - 320X200 graphics mode check
6 - 640X200 graphics mode check
7 - Screen paging check
8 - Light pen check
9 - Color video check
10 - Sync check
11 - Run all above checks
0 - Exit
Enter selection number:
C-12 Performing System Diagnostics