Apple Performa 6400/180 - Manual (Page 95)

Troubleshooting Symptom Charts/Miscellaneous - 21
Miscellaneous
Screen shows “Sad
Macintosh” icon and
black vertical lines;
screeching sound
1 Replace RAM DIMMs on logic board.
2 Replace logic board. Retain customer’s DIMMs.
Headphone jack does
not operate correctly
1 Verify that headphone jack is seated properly.
2 Replace front panel control board.
3 Replace chassis/wiring harness.
Note:
The chassis/wiring harness is not a separate
replacement part. Order the metal chassis that contains the
chassis/wiring harness.