IBM 5531 Operator's Manual page 163

Problem Determination Procedures
Test 9000 -IBM Industrial Color Display
(continued)
Typical 7534 display
6. Does the screen look like one of the illustrations above?
YES - For 5532 display, continue with step 7.
For 7534 Display continue with step 8.
NO - Have the display serviced.
7. Are the black areas approximately the same size?
Coarse
raster
Note: Answer this question NO only if one area is less than half the width of the other.
YES - Continue with the next step.
NO - Have the display serviced.
8. 7534 Display:
Turn the left (vertical size 1) control until the black area just disappears.
5532 Display:
Turn the left (vertical size) control until the black areas just disappear. If one of the black
areas disappears before the other, continue to turn the control until the second black area is
gone.
9. Is the entire screen white?
YES - Go to Step 14.
NO Continue with the next step.
5-9000-2
IBM Industrial Color Display