As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER FLAP RETRACTION, WITH FLAPS UP AND LED LIGHT GREEN, "A" SYSTEM QUANTITY DECREASED TO ZERO. WITH LOSS OF "A" SYSTEM PRESSURE RAN APPROPRIATE EMERGENCY CHECKLISTS. FOUND NR 4 SLAT ACTUATOR BODY FAILED AT ENDCAP WHERE ROD EXITS THE HOUSING. REMOVED AND REPLACED L/E SLAT ACTUATOR IN REF TO 727-200 MM, 27-81-032-4. OPS CHECKED NORMAL.