What was found
FLT# 830, SDQ-BOS. AFTER EXTENDING THE LANDING GEAR L/G GEAR NOT DOWNLOCKED ECAM OCCURRED RAN QRH AND HAD A NORMAL EXTENSION ; TROUBLSHOT IAW TSM 32-31-00-810-859A, R/R NLG OPENING SAFETY VALVE 2630GM IAW AMM 32-31-19, OPS CHECK OK, LEAK CHECK OK.