As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE STUCK IN FULL REVERSE. REV ISLN LIGHT ILLUMINATED. EICAS 'REV' DISPLAYED GREEN. FORWARD THRUST LEVERS COULD NOT BE ADVANCED. FRM CODE 78 34 08 CREW COMMENTS: R REV ISLN VAL ON EICAS. TRY TO OPERATE THRUST REVERSER, STUCK IN OPEN POS. AFTER TROUBLESHOOTING FOUND ON STOW VALVE DISPATCH PIN FITTED. REMOVED PIN. OPERATED THRUST REVERSER, OPERATION NOW NORMAL.