I had the same issue. Got on the phone with Dyson. THe vacuum has a safety feature where if the motor gets too hot it cuts off. You have to leave it for 45 minutes or so and then it will work again. There is an underlying issue though. My problem was the black gasket thats in the debris bin shifted, probably from when emptying i pushed it on something. The black gasket should actually hang off the bottom like a skirt
and the 2 groves should fit in on the groves of the gray mechanism. This seal is what provides 100% suction. Because of this..my vaccumm has been accumulating pet hair by the belt which i hear alot of people talking about and especially in the filter area. This is because I broke the seal by not having the gasket in place properly and it wasnt sucking 100%. They are sending me a complete new cyclone unit which has the debris catcher as well as she said its probably so caked up with debris it will never work again 100%. no questions asked they are sending it to me free of charge.
So if you remove the clear cyclinder debris catch thing all you will have is the purple cyclone on top and on the bottom is the black rubber gasket....if that shifted and is no longer hanging off...call dyson cause your vacuum is probably caked up...it will never work properly...they will send you a new part