Apple Performa 6400/180 - Manual (Page 88)

Troubleshooting Symptom Charts/CD-ROM Drive - 14
CD-ROM Drive
CD not recognized or
no power.
1 In a Power Macintosh 6500, reseat the logic board to
reestablish logic board-to-chassis connection.
2 Remove hard drive to see white pull tab. If anything but
Foxconn is printed on pull tab, replace the chassis (P/N
922-2707).
3 Check that power supply is set to the correct voltage.
4 Replace power supply if switch is in the incorrect position.