Apple Macintosh Performa 577 - Manual (Page 21)

Troubleshooting Symptom Charts/Video
(Continued)
- 4
Video
(Continued)
Picture breaks into
diagonal lines, or
picture rolls
vertically or
horizontally
1 Perform video adjustments. Refer to “Video” in Adjustments
chapter.
2 Replace analog board.
Out of convergence
(color bleeds from
text or lines)
1 Perform convergence adjustment. Refer to “Convergence” in
Adjustments chapter.
2 Replace analog board.
3 Replace CRT.
Black screen spots
(burnt phosphors)
Replace CRT.