What was found
DURING CLIMBOUT FROM YUL, LANDING GEAR DOOR OPEN LIGHT REMAINED ON AFTER GEAR WAS RETRACTED. RECYCLED GEAR AND LIGHT EXTINGUISHED. FLIGHT CONTINUED TO MSP AND LANDED WITHOUT INCIDENT. CYCLED MAIN GEAR DOORS SEVERAL TIMES, ALL CHECKED OK. DISCREPANCY COULD NOT BE DUPLICATED. AIRCRAFT RETURNED TO SERVICE.