As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER SELECTING FLAPS 30, WE RECEIVED A TE FLAP DISAGREE MESSAGE. WE EXECUTED A GO AROUND AND DECLARED AN EMERGENCY. AFTER RUNNING THE QRH FOR FLAPS GREATER THAN 20 (INDICATING ROUGHLY 23 DEGREES WITH FLAPS STILL SELECTED AS 30) WE LANDED AND TAXIED TO THE GATE UNEVENTFULLY. REMOVED & REPLACED NR 1 FLAP/SLAT ELECTRONICS UNIT IAW MM 27-51-01-2-0 & 27-51-01-742-085. ALL INDICATIOINS NORMAL. PERFORMED FLAP HANDLE TRANSMITTER DETENT TEST IAW IAW MM 27-58-01-5-0. ALL INDICATIONS NORMAL.