As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLAP/SLAT EXTENSION, SLATS STUCK BETWEEN 15 DEG AND 30 DEG. WOULD NOT RETRACT. FOUND THE FEEDBACK PPU, (FPPU) & LT WING (APPU) READING INCORRECTLY. REMOVED AND REPLACED FPPU REF MM 27-81-19-4. STILL REQUIRES RII FOR INSTALL & OPERATIONAL TEST REF 27-84-00-5. REMOVED & REPLACED LT WING APPU REF MM 27-86-11-4.