Specifications

Troubleshooting Symptom Charts/Video
(Continued)
- 5
Video
(Continued)
Areas of the screen
have blotches of color
1 Since this type of problem (purity) is often caused by
magnetic fields in the area, place unit in another location to
see if symptom disappears, changes in its intensity, or
changes location on the screen.
2 Turn off the monitor power switch, wait five minutes, then
turn it back on. This enables the monitor’s internal
degaussing coil.
3 Severe magnetic field problems require the use of an
external degaussing coil. (Degaussing coils can be purchased
at most larger electronic parts stores.)
Screen is too bright;
adjusting Brightness
control does not
lower intensity
1 Perform the “Cutoff and White Balance” procedure in the
Adjustments chapter.
2 Replace the CRT/video board.
3 Replace the main deflection board.
4 If you suspect a defective CRT, contact Apple Technical
Support.