The reason that the brush won't spin when it is put on the carpet is because the belt is stretched or worn. When this happens after use the belt cannot turn the brush roll against the resistance of the carpet. You simply need to change the belt. You can get replacement belts here:
106766 type 2 the cord for power head shorted at plug at top of canaster. part # do i need ocomplete...
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106766 type 2 the cord for power head shorted at plug at top of canaster. part # do i need ocomplete hose?