What was found
AFTER TAKEOFF MLG HANDLE UP, ECAM CAUTION: L/G GEAR NOT UPLOCKED. CYCLED MLG PER ECAM ALL GEAR UP & LOCKED OK. MX CYCLED MLG, OPS CHK GOOD. ACFT RETURNED TO SERVICE. WITHIN 8 CYCLES DISCREPANCY RETURNED. ACFT MX FERRIED BACK TO PHX. SEVERAL SENSORS INSPECTED, ADJUSTED & REPLACED IAW AIRBUS MM. NLG RESTRICTORS 2535GM, 2536GM & 2691GM REPLACED. MLG SELECTOR VALVE 40GA CHANGED, NLG DOOR BYPASS VALVE REPLACED. R & R RELAYS 48GA AND 53GA. TEAR DOWN REPORT CONFIRMS REPLACEMENT OF MLGCU. FOUND S1 SWITCH FAULTY. SWITCH REPLACED & UNIT TESTED OK. ALL WORK PERFORMED IAW CMM 32-31-13 REV 9.