As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB-OUT GOT INTERMITTENT SMOKE CAUTION LIGHT. RETURNED TO FIELD. UPON OPENING CARGO BAY DISCOVERED A RAMP RADIO/CELL PHONE HAD BEEN LEFT BY GROUND CREW IN ON POSITION. PERFORMED OPERATION CHECK OF BAGGAGE COMPARTMENT SMOKE DETECTION SYSTEM PER AMM TASK 26-15-00-710-801. OPERATION CHECK GOOD. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.