As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER GEAR RETRACTION, THE LEFT MAIN GEAR UNSAFE LIGHT REMAINED ON. RIGHT HYDRAULIC PUMPS ON HIGH. AT GEAR UPLATCH CHECK, THE LIGHT WENT OUT. GEAR RECYCLED ONE TIME BEFORE UPLATCH CHECK WITH THE LIGHT STILL ON. REPLACED THE LEFT GEAR DOWN SENSOR IAW DC-9 MM 32-60-01-2 AND PERFORMED ADJUSTMENT AND TEST. NO DEFECTS NOTED.