As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING GO AROUND FLAPS WOULD NOT RETRACT AND FLAP CAWS WARNING ILLUMINATED. SYSTEM WAS TROUBLESHOT TO A FAULTY FLAP CONTROL AND WARNING UNIT. REPLACED UNIT AND PERFORMED FUNCTIONAL TESTS. FLAP SYSTEM FAILED ON THE GROUND AFTER SEVERAL EXTENSIONS AND RETRACTIONS. FURTHER TROUBLESHOT SYSTEM TO A FAULTY FLAP POWER DRIVE UNIT. REPLACED POWER DRIVE UNIT AND PERFOMED SATISFACTORY OPERATIONAL CHECKS.