As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AVIONICS SMOKE WARNING LIGHT CAME ON AFTER TAKEOFF AS GEAR CAME UP. RETURNED TO AIRPORT. NO SIGNS OF SMOKE ODOR OR HEAT FROM TIME LIGHT WENT ON UNTIL AFTER SHUTDOWN. AVIONICS SMOKE WARNING LIGHT STILL ON AFTER SHUTDOWN. REPLACED DETECTOR.