What was found
AFTER GEAR RETRACTION, #1 SIDE SHOWED UNSAFE INDICATION FOR DOORS, GEAR, AND HANDLE REMAINED ILLUMINATED. #1 DOORS REMAINED OPEN. PERFORMED ALTERNATE GEAR EXTENSION AND SHOWED 3 GREEN. REMOVED FROM SERVICE. GEAR AND MLG DOOR PINS INSTALLED. CLEANED AND INSPECTED #1 UPLOCK ASSY. FOUND ONE EXTENSION SPRING BROKEN. REMOVED AND REPLACED SPRING IAW Q400 TASKS 32-31-21-000-803 AND 400-803. OPS CHECK C/W 6 TIMES. OPS CHECK GOOD. LUBED #1 UPLOCK ASSY IAW AMM TASK 12-20-01-640-803. GEAR AND MLG DOOR PINS REMOVED AND STOWED. AIRCRAFT RETURNED TO SERVICE.