What was found
(CAN) UNABLE TO PERFORM WATER BUCKET OPERATIONS (FIRE SUPPRESSION) DUE TO ELECTRICAL DEFECT. TROUBLESHOOTING CARRIED OUT ON SYSTEM AND PRINTED CIRCUIT BOARD 25 IDENTIFIED AS CAUSE DUE TO HAEAVY CORROSION ON CONTACT POINTS OF BOARD. BOARD WAS REPLACED WITH NEW UNIT AND SYSTEM CHECKED SERVICEABLE. THIS BOARD ALSO CONTROLS OTHER AIRCRAFT SYSTEMS SUCH AS COMMUNICATIONS, CARGO HOOK OPERATIONS, ETC. IT IS CURRENTLY NOT PART OF THE MANUFACTURE'S INSPECTION PROGRAM AS A POINT OF INSPECTION.