Epson I+ - Manual (Page 110)

If any colors are displayed incorrectly, first check the adjustment of your
monitor, and make sure that both ends of the cable are plugged in firmly. If a
problem still exists, press N and Enter to display the error message.
640x200 graphics mode check
To check your 640x200 graphics mode, press 6 and Enter.
The screen displays three patterned squares against a black background,
as shown below.
640X200 GRAPHICS
MODE CHECK
Is the display correct
(Y/N)?
If the patterns on your screen are clear and distinct, press Y and then
Enter.
If any pattern is not displayed clearly, first check the adjustment of your
monitor, and then make sure that both
ends
of the cable are plugged in
firmly. If a problem still exists, press N and Enter to display the error
message.
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