Re: Dyson DC04 throwing belt
It also worth checking the brushroll housing (bright green thing). Any worn patches on that will cause the machine to snap belts constantly.
Belts jumping off?!?!?! See if there’s any rust on the motor shaft, and stop bumping it over rugs/mats.
There’s also a thin metal rod, that holds the belt in place. This should be part of the brushroll/belt cover that you remove to get access to the belt. Is that rod still there?
Power off before investigating please.