As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ARRIVAL, AT SELECTION OF FLAPS TO 20, ONE FLAP POINTER REMAINED AT 15 WHILE OTHER CONTINUED TO 20. NO EICAS MESSAGE OR TRAILING EDGE LIGHT ILLUMINATED. LANDING EXECUTED AT FLAPS 20. DURING APPROACH BOTH POINTERS RESET TO 20. UNEVENTFUL LANDING AND ROLLOUT. OPERATED FLAPS NUMEROUS TIMES AT GATE, COULD NOT DUPLICATE THE PROBLEM. REMOVED AND REPLACED THE NR 1 FSEU. ACCOMPLISHED ALL REQUIRED CHECKS AND ALL CHECKED NORMAL.