As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3924 DURING THE CLIMBOUT THE CREW DISCOVERED FAILURE OF FLAPS. THE CREW REPORTED THAT THE FLAPS WOULD NOT RETRACT FROM 9 DEGREES. AN EMERGENCY WAS DECLARED. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE LEFT VELOCITY SENSOR, AND THE RIGHT FLAP VELOCITY SENSOR AND CONNECTOR. AIRCRAFT RETURNED TO SERVICE.