As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MAINTENANCE INSPECTION RAMP NOTICED SMOKE IN CABIN. THE AIRCRAFT WAS REMOVED FROM SERVICE. RAN APU IAW 49-10-00 TURN BOTH PACK ON RAN FOR 2 HOURS IAW 21-00-00, TURN ALL LIGHTS ON IAW 33-21-00 HAD LIGHTS ON FOR 2 HOURS. NO PROBLEMS NOTED OPERATIONAL WAS CHECKED GOOD. THE AIRCRAFT RETURNED TO SERVICE.