What was found
AFTER TAKEOFF THE LG FAILED TO RETRACT WHEN THE GEAR HANDLE WAS SELECTED TO THE UP POSITION. THE TWO MAIN GEAR DOORS OPENED, 2 RED LIGHTS, BUT THE MAIN GEAR FAILED TO MOVE. THE GEAR HANDLE LIGHT WAS IN FLASHING MODE. WE CYCLED THE GEAR ONCE WITH THE SAME RESULT. WHEN THE GEAR HANDLE WAS SELECTED DOWN WE GOT 3 GREEN LIGHTS & NO RED, INDICATING THE GEAR WAS DOWN & LOCKED & THE GEAR DOORS WERE IN THE CLOSED NORMAL POSITION. REMOVED AND INSTALLED NEW NLG PROXIMITY SWITCH. ADJUSTED TO MINIMUM GAP IAW MM 32-61-49-900-801 OPS CHECK GOOD. REMOVED & INSTALLED NEW PCB 10GW REF F2000 MM 20-00-00-910-803 AND IPC 24-63-30-35 OPS CHECK GOOD. PERFORMED LANDING GEAR RETRACTION AND EXTENSION IAW MM 32-31-00-860-801 OPS CHECK GOOD NO FAULTS FOUND. CIRCUIT BOARD (PN: C1626-2, SN: 192), PROXIMITY SWITCH (PN: D22859000-2, SN: UNK003).