What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS ON CLIMB OUT FROM MEX, RAISED LANDING GEAR LEVER AND THE GEAR REMAINED DOWN. RAN GEAR DISAGREE QRH 14.11 CHECKLIST AS ALL LIGHT (RED, GREEN, AND NOSE LIGHTS) WERE ILLUMINATED, THEN GEAR RETRACTED. MAINTENANCE CLEANED AREA AROUND MANUAL EXTENSION SYSTEM ACCESS DOOR. INSPECTED DOOR SWITCH AND CHECKED OPERATION IAW 32-34-00. ACCOMPLISHED ALTERNATE LANDING GEAR TEST IAW AMM 32-31-51 CHECKED OK. ACCOMPLISHED BITE TEST OF PSEU IAW AMM 32-09-10. NO FAULTS NOTED.