As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAS/PHX - FLT NR 312 - CREW REPORTED AIRFRAME VIBRATION AT TAKEOFF AND ELECTED TO RETURN TO LAS. AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND GROUND ELECTRICAL SERVICE DOOR OPEN. NO DAMAGE TO AIRFRAME NOTED. MAINTENANCE SECURED DOOR. AIRCRAFT RELEASED FOR SERVICE. (M)