As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 4914 - CREW REPORT AVIONICS SMOKE LIGHT ILLUMINATED IN-FLIGHT. AIRCRAFT LANDED AND RETURNED TO ITS GATE WITHOUT FURTHER INCIDENT. INSPECTED AVIONICS BAY AND FOUND NO EVIDENCE OF A FIRE. CLEANED SMOKE DETECTOR AND RETURNED TO SERVICE.