IBM 5150 Hardware Maintenance Manual page 59

Each line on your Display should match the description of
that line.
DISPLAY ATTRIBUTES
~ 'B],o'\
,"' " ,:;":,,,
1)"1'1.,
THIS LINE IS AT NORMAL INTENSITY.
THIS LINE IS INTENSIFIED.
THIS LINE IS IN REVERSE VIDEO.
THIS LINE IS BLINKING.
THIS
liN!.!§
UNDERLINED.
IS THE SCREEN CORRECT? (YIN)
())
•
IS YOUR DISPLAY SCREEN CORRECT?
NO
Replace IBM Monochrome Display and Parallel
Printer Adapter. See Section 3, "Removal/
Replacement. "
YES
400-6