As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENROUTE CREW NOTICED SMOKE COMING FROM AUDIO CNTRL PANEL, PULLED CIRCUIT BREAKER, SMOKE STOPPED. CREW DONNED O2 MASKS AND ELECTED TO RETURN TO ORIGINATING AIRPORT FOR NORMAL LANDING. MAINTENANCE REPLACED LT AUDIO CNTRL PANEL AND AIRCRAFT RETURNED TO SERVICE (TC NR 20070411006)