As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 3347- THE CREW REPORTED A LOUD RUMBLE NOISE PASSING THROUGH 19K COMING FROM THE NOSE, AND DIFFICULTY MAINTAINING 1000 FPM CLIMB AT 23K TO 24K. THE AIRCRAFT LANDED AT IAH WITHOUT INCIDENT WHERE MAINTENANCE REMOVED AND REPLACED THE NOSE THIRD UPLOCK PROXIMITY SWITCH. OPERATIONALLY CHECKED WITH NO DEFECTS. THE AIRCRAFT WAS TEST FLOWN SATISFACTORILY, AND WAS THEN APPROVED FOR RETURN TO SERVICE.