Epson LT-286 - Manual (Page 134)

Monochrome Adapter Check
To check the monochrome adapter, press 1 and then Enter.
The computer checks the video RAM (display memory) on the
display adapter by writing certain data to memory, then reading it
back and comparing it to the written data. The computer also tests
the video enable signal of the display controller chip.
Attribute Check
To check the display attributes of the adapter card, press 2 and
then Enter.
A series of messages appears showing examples of all the possible
display attributes (normal intensity, high intensity, blinking,
reverse, and underlining). Check the information that appears on
your screen, and then respond to the prompt:
I s
t h e d i s p l a y
c o r r e c t ( Y / N ) ?
Press Y and then Enter if the display is correct.
If the display attributes are not correct, adjust the brightness and
contrast on your display monitor. If they are still incorrect, press N
and Enter.
Character Set Check
To check your character set, press 3 and then Enter. The character
fonts included in the internal character generator are displayed on
your screen. Compare your screen display to this illustration:
Performing System Diagnostics D-9