As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TE FLAP DISAGREE EICAS WHEN FLAPS 20 SELECTED AT APPROX 170 KIAS, FLAP INDICATION SHOWED BETWEEN 15 AND 20. COMPLETED QRH 9.1.17 AND LANDED USING FLAPS 20.EMERGENCY DECLARED. ***EMERGENCY DECLARED***. TROUBLESHOT IN REF TO FIM 27-51 FAULT TREE 808 WITH NO FAULTS NOTED. PERFORMED GVI OF THE L/H AND R/H FLAP DRIVE COMPONETS WITH NO FAULTS NOTED. REMOVED AND REPLACED THE L/H I/B #4 FLAP TRANSMISSION IAW AMM 27-51-06-4. OPS CHECK GOOD WITH NO FAULTS NOTED.