What was found
ON APPR INTO KONT, PUT LDG GEAR HANDLE DOWN AND IT WAS STRANGELY QUIET, GEAR DID NOT COME DOWN. TRIED SYS 2 WITH SAME RESULT. EXECUTED GA AND MANUALLY EXTENDED GEAR. UPON LANDING/ENGINE SHUTDOWN, ECAM SHOWED C/B MONITOR OPEN, "LDG GEAR EXTEND CONTROL" C/B HAD POPPED. FOUND CONNECTOR ON LANDING GEAR SELECTOR VALVE 3GA-A FOULED WITH HYDRAULIC RESIDUE. CLEANED, REPLACED 3 AMP CIRCUIT BREAKER 1GA REFERENCE WIRING DIAGRAM 32-31-01 PAGE 1, AND CHAPTER 20-16-00-2. PERFORMED OPERATIONAL TEST OF SYSTEM 4 TIMES, ALL CHECKS GOOD, NO FAULTS AND ON EACH TEST THE CIRCUIT BREAKER REMAINED IN, PER MM 32-31-12-6.