Hello,
Do you have a voltage meter?If not be sure the vacuum is unplugged look at the hose from the canister to the handle.Does it have any damage or kinks in it?If not unhook the hose from the canister &look at the three pins that come out of the plug on the side of the hose &also at the canister do the electrical connector's look burnt or damaged?
Also look under the bag in the canister there is a cord that runs to the end of the canister where you connect the hose.If the cord in the canister under the bag or the hose (which has a cord mounded into it) is damaged they need to be replaced.If the hose is damaged to the point the cord in it is broken you can get a replacement hose at sears .com keep in mind if the hose is to be replaced get the replacement complete assemble with the handle&nozzle that plugs into the canister attached for replacing just the hose is not a very easy thing to.