Apple lc 520.550.575 Servicehandbuch

 

 Troubleshooting

Symptom Charts/Video

 

 (Continued)

 

 - 5

 

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 Disconnect internal floppy drive, CD-ROM drive, and hard 

drive.

4 Replace analog board.

Out of focus

1 Perform focus adjustment. Refer to “Focus” in Adjustments.

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.

Raster size too short/

tall or narrow/wide

1 Adjust horizontal or vertical size control. Refer to 

Adjustments chapter.

2 Replace analog board.