IBM 3745 Series, Installation And Maintenance Manual

Page: 103 / 270

Display
If the screen is rolling, replace the display assembly. If that not correct the problem,
replace the video adapter (if installed) or replace the system board.
If the screen is not rolling, do the following to run the display self-test.
1. Power off the computer and display.
2. Disconnect the display signal cable.
3. Power on the display.
4. Turn the brightness and contrast controls to their maximum setting.
5. Check for the following conditions:
¹
The screen should be white or light gray, with a black margin (test margin)
on the screen.
¹
You should be able to vary the screen intensity by adjusting the contrast
and brightness controls.
Note
The location of the test margin varies with the type of display. The test
margin might be on the top, bottom, or one or both sides.
If you do not see any test margin on the screen replace the display. If there is
a test margin on the screen, replace the video adapter (if installed) or replace
the system board.
Note
During the first two or three seconds after the display is powered on, the
following might occur while the display synchronizes with the computer.
¹
Unusual patterns or characters
¹
Static, crackling, or clicking sounds
¹
A “power-on hum” on larger displays
A noticeable odor might occur on new displays or displays recently removed
from storage.
These sounds, display patterns, and odors are normal; do not replace any
parts.
If you are unable to correct the problem, go to “Undetermined Problems” on
page 3-23.
Chapter 3. Service Processor Troubleshooting
3-19