Happens to PW123E engines as well, but is due seal failure between the 1st and 2nd stage turbine.
Symptoms of partial or total component failure are:
Significant engine vibration when selecting Condition Levers to MAX after engine start, coupled with vibration through the related Condition Lever.
No propeller rotation after stabilised idle Nh during start - described as Power Turbine Lockup.
A propeller which cannot be rotated by hand - Power Turbine Lockup.
A propeller which decelerates quickly after engine shutdown.
The symptoms described are caused by fragments of the failed seal or associated components lodging between the rotating shaft and seal housing. Information to date suggests that if a component is faulty, failure is likely to occur between 1100 and 1500 hours of engine operation. In all recorded cases, the internal seal remnants have been ingested by the engine with no catastrophic effect on engine operation. Operation with the seal missing has not caused secondary failures.