As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FL 1756 - AT FL350, CREW NOTED THAT THE LEFT THROTTLE WAS FROZEN. FLIGHT RETURNED TO PIT. DESCENDING THROUGH FL230, THE THROTTLE LOOSENED UP. FLIGHT LANDED WITH NO FURTHER INCIDENT. MAINTENANCE REPLACED THE THROTTLE CABLE FROM THE PYLON TO THE CARGO COMPARTMENT. (M)