As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AT 5000 FT IN CLIMB FROM DEPARTURE, CREW RECEIVED EICAS MESSAGE "AVIONICS SMOKE". EMERGENCY DECLARED WITH ATC AND RETURNED WITH CFR ON ALERT. FLIGHT LANDED APPROXIMATELY 5000 KGS OVERWEIGHT. MOC ADVISED. CREW REPORT NORMAL APPROACH AND NORMAL RATE OF DESCENT. REPLACED AVIONICS SMOKE DETECTOR IAW AMM 26-15-15. TEST OK.