The problem is either that the turbine is rusted and won't turn anymore, or the plastic piece on the brush block that fits up into the turbine is broken. Remove the brush block by squeezing the plastic latches that hold it in the machine and inspect. There should be one square plastic piece on one of the round brushes that sticks up further than the rest. If not, you'll need to purchase a new brush block. If the brush block is good, take a flat bladed screwdriver and stick it into the square white hole where the brush block stalk would normally fit. Gently try to turn the turbine by hand. Sometimes you can work it loose. If it won't turn, you'll need to purchase a new turbine.
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