As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FAILURE OF INTERNAL LOCK MECHANISM OF THE FLEX SHAFT LOCK ON PNEUMATIC DRIVE UNIT. FAILURE OCCURRED DURING THRUST REVERSER STOW CYCLE. THRUST REVERSER ANNUNCIATOR REMAINED ON. FURTHER INVESTIGATION REVEALED THE PDU FLEX SHAFT LOCK FAULTY WITHIN THE UNIT.