As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF, THE GEAR WARNING HORN SOUNDED WITH THE STRUT EXTENSION, THE 4 RED GEAR UNSAFE LIGHTS ILLUMINATED. RECYCLED GEAR AND LIGHTS REMAINED ILLUMINATED. FLIGHT RETURNED TO MSP. MAINTENANCE REPLACED THE MAIN LANDING GEAR PROXIMITY CONTROL.