As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED AT 45,000 FT THE INITIAL POWER REDUCTION FROM CLIMB POWER TO 90% YIELDED AN AUDIBLE "THUD" AND HOT AIR SMELL. THE MAINTENANCE VENDOR TROUBLESHOT AND DETERMINED THE LEFT AND RIGHT FLOW CONTROL VALVES TO BE DEFECTIVE. THE VALVES WERE REPLACED. OPS AND LEAK CHECKS WERE SATISFACTORY. THE AIRCRAFT WAS RETURNED TO SERVICE