Apple 578 Personal Computer User Manual


 
Troubleshooting Symptom Charts/Video
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- 5
Video
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Screen jitters or
flashes
1 Verify that adjacent computer equipment is properly
grounded. Move electrical devices away from monitor.
Temporarily shut off all fluorescent lights in area.
2 Check that all ground cables are secure.
3 Replace analog board.
Out of focus 1 Perform focus adjustment. Refer to “Focus” in Adjustments
chapter.
2 Replace analog board.
3 Replace CRT only if one part of display remains out of focus
despite adjustment of focus controls to their limits.