Clean or Replace the filter(s) and check the Cyclone, ports and hose for clogs. The reason why the dyson may be cutting out is a thermoprotector on the motor. When there is no suction, The motor gets hot due to lack of adequate ventilation. When this happens, the thermoprotector cuts the power to the motor to avoid a fire hazard due to overloading.
Alexander 24, Maryland
December 2006