Apple Macintosh Performa 577 - Manual (Page 23)

Troubleshooting Symptom Charts/Video
(Continued)
- 6
Video
(Continued)
Flashing or wavy
screen or monitor
emits high-pitched
noise
Replace analog board.
Raster size too short/
tall or narrow/wide
1 Adjust horizontal or vertical size control. Refer to
Adjustments chapter.
2 Replace analog board.
Linearity bad (size of
text/graphics differs
at top, bottom, or
sides of screen)
1 Perform video adjustments. Refer to “Video” in Adjustments
chapter.
2 Replace analog board.