What was found
DURING APPROACH THE FLAP GAUGE (BOTH NEEDLES) REMAINED STUCK AT ZERO, REGARDLESS OF FLAP POSITION, HOWEVER THE GREEN "F" ON THE ADI SPEED TAPE APPEARED TO OPERATE NORMALLY. FLAPS WERE VISUALLY VERIFIED DOWN BY A FLT CREW MEMBER AT THE WING POSITION. NO EICAS MSGS. REMOVED AND REPLACED FLAP POSITION INDICATOR PER AMM 27-58-02-401. OPS CHECK GOOD. ROTABLE PARTS CHANGE WAS INDICATED - TT # 1467911 SN OFF 01355 INDICATOR, POSI OFF 19-2758-9-0001 1355 ON 19-2758-9-0001 1325.