What was found
AFTER TAKEOFF WITH GEAR SELECTOR UP, FOR MORE THAN 30 SECONDS RECEIVED GEAR DISAGREE WARNING MESSAGE. MAIN LANDING GEAR SHOWED WHITE HASH MARKS. NOSE GEAR SHOWED RED HASH MARKS. MESSAGE PERSISTED FOR MORE THAN 20 SECONDS. COMPLIED WITH QRH. TURNED ON HYD PUMP 2B, 3B WAS ALREADY ON FOR THE MEL. SELECTED EMERGENCY EXTENSION HANDLE. MAINS EXTENDED. NLG DID NOT EXTEND. SELECTED MLG DOWN, THEN NOSE SHOWED DOWN AND GREEN. SELECTED EMERGENCY EXTENSION HANDLE TO NORMAL AND NLG DOOR CLOSED. ALL MESSAGES EXTINGUISHED. R & R BOTH NR 3 ALTERNATING CURRENT MOTOR PUMP'S 3A AND 3B AND RESERVOIR.