While vacuuming the beater stopped.

ok what u have 2 do is replace the belt. real easy so i will tell u how,first unplug the vacuum cause you need your hands for the next step. now turn it over and the part where the roller sits your going to have some screws prolly 2 take them out the cover should come off youll see the roller the pulley and the broken belt if your lucky find the belt size replace it put back together and you should be back in business....

HOPE THIS HELPS GOOD LUCK