FOD in the lever slots, etc), the thrust can't retard even if the A/T is commanding it? Or does the A/T system allow for the lever position to be over-ridden if it detects such a fault?
If the thrust lever is stuck, Happens sometimes on the 146/AVRO. (Simply freezes if there is moisture in the cables) It will remain stuck and A/T not be able to control, and unless it unfreezes as you descend into warmer tempertures you may have to shut down the engine. (At least there are 3 left)
AA