What was found
ON CLIMB OUT, CREW REPORTED THE LT MAIN LANDING GEAR RED AND GREEN LIGHTS ILLUMINATED WHEN GEAR WAS RETRACTED, CYCLED GEAR WITH SAME RESULTS. WHEN GEAR WAS EXTENDED, INDICATION WAS NORMAL. FLT RETURNED TO FIELD AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINT REMOVED AND REPLACED LOGIC CARDS M986 AND M988 AND LUBRICATED THE LANDING GEAR ASSEMBLY. PERFORMED OPER CHECK OF MLG IN ASSOC WITH MM WITH HYDRAULIC MULE AND AIRCRAFT HYDRAULIC SYSTEM. OPERATIONAL CHECK NORMAL ON GROUND. PROBLEM REPEATED, ON CLIMB OUT, THE LT MLG RED AND GREEN LIGHTS ILLUM UPON GEAR RETRACTION. MAIN REMOVED AND REPLACED LOGIC CARD M987 (DOWN AND LOCKED). OPS CHECK GOOD.