As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SFO - UPON RETRACTING FLAPS FROM 1 DEGREE TO 0 DEGREES LEADING EDGE LIGHT AND LEADING EDGE SLAT DISAGREE MESSAGE ILLUMINATED. EMERGENCY DECLARED RETURNED SFO WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED NUMBER 1 AND 20 ROTARY DRIVE ACTUATORS. REMOVED AND REPLACED FLAT SLAT ELECTRICAL UNIT. SYSTEM GROUND CHECK NORMAL OPERATION.