As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AC WAS IN FOR HEAVY CHECK FOUND LT WING AILERON BOTH PCU'S HAS CORRODED HARDWARE (PCU REQUIRE CHANGE NO CORROSION ALLOWED). REMOVED AND REPLACED PCU'S, IAW AMM TASK 27-12-01-400-801-A SEE AAR NRC 4500833-5000-0011 FOR WORK PERFORMED. AC REMAINS IN YQG FOR COMPLETION.