As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O WITH GEAR HANDLE UP GEAR DISAGREE AND GEAR DOORS LIGHT ILLUMINATED. THE LT GEAR INDICATOR SHOWING UNSAFE. PUT GEAR HANDLE DOWN AND THE GEAR DOORS LIGHT REMAINED. FOUND LEFT MAIN GEAR DOOR BYPASS VLV PINNED. STOWED PIN. MAIN DOORS OPERATION NORMAL. OK FOR SERVICE. ETOPS CATEGORY 'B': DIVERSION OR TURNBACK.