Specifications
Troubleshooting Symptom Charts - 6
Screen Color
Screen is one
predominant color
1 Remove video cable at computer and check for damaged or
missing pins.
2 Verify that video cable is securely connected to computer.
3 Open Monitors & Sound control panel, and click Color icon.
Verify that a standard white point has been selected (D50,
6500, or 9300). Then click Recalibrate button
(recalibration can take 20 seconds to 2-1/2 minutes).
4 The CRT/video board might not be properly secured on the
neck of the CRT. Check that CRT socket connection is tight.
5 Call Apple Technical Support. (In the US, call 1-800-919-
2775, option 3.)
Screen shows blotches
of color
1 Shut down computer and monitor, and move them to an area
where there are no external speakers or large metal objects
such as benches, cabinets, etc.
2 Wait 20 minutes before turning on computer and monitor. If
you see some improvement, repeat this step as needed.
3 Degauss display with a hand-held degaussing coil. (You can
purchase a degaussing coil for about $25 at most larger
electronic parts stores.)
4 From the Monitors & Sound control panel, click Geometry
icon and then click Rotate. Adjust rotation to minimize color
blotches.
5 Call Apple Technical Support. (In the US, call 1-800-919-
2775, option 3.)
Screen Brightness
Screen is very bright
(monitor might shut
down)
1 Adjust front panel Brightness and Contrast controls.
2 Check and adjust EHT (high voltage) using Display Service
Utility and high-voltage probe. Refer to “Checking High
Voltage” in this chapter.
3 Call Apple Technical Support. (In the US, call 1-800-919-
2775, option 3.)
Two-inch (50 mm)
vertical bar on right
side of screen has
lower brightness
than rest of screen
1 Check cable connections.
Important:
Be sure the ADB and video cables from the
monitor are connected to the ports on the computer
.
2 Check environmental factors for interference (refer to
“First Checklist” at the beginning of this chapter).
3 Replace main deflection board.
4 Call Apple Technical Support. (In the US, call 1-800-919-
2775, option 3.)