From techguy, Have you checked washable filter(located in top of cyclone--DC04 model,or if a DC07 model--in a removable"drum" on right hand side of motor/brush head--ensure that this is not blocked/causing restriction of suction.finally check post motor (HEPA)filter--found in a container above motor--a circular locking "plate" will need to be (very carefully)removed with a coin(2pence coin)--being used to depress a small tab ,(viewed directly in front of locking plate.Note: The post motor filter as described,is directly below cyclone/dust container.Last of all the model number for your dyson,should be located on underside of motor/brush head--that is assuming it has not been removed/defaced.VERY LAST,BUT OBVIOUS--Have you checked "u"tube,valve assembly by filter drum,and both moulded pipe passage's in the main body for any possible blockage?
Techguy., February 2011
