What was found
FLAPS WILL NOT RETRACT BEYOND 7 DEG WITH THE FLAP HANDLE IN THE 0 POSITION. RECEIVED ACFT WITH FLAPS STUCK HARD AT 15 DEGREES. ATTACHED HYDS AT EXTEND AND RETRACT LINES OFF OF FLAP CONTROL VALVE. FLAPS WOULD NOT EXTEND OR RETRACT WITH APPLIED HYD PRESSURE. MEASURED ACTUATOR ROD LENGTHS WITH HYD PRESSURE APPLIED, THE RT ACTUATOR WOULD MOVE 1/4 INCH WHILE THE LT ACTUATOR REMAINED LOCKED. REMOVED LT FLAP ACTUATOR AND INSTALLED CUSTOMER SUPPLIED P/N 9912007-2 S/N 2568. WORK WAS PERFORMED IAW MM 27-51-04.