If your vacuum cleaner suddenly stops working one day, there's a decent chance that either a fuse has blown on the inside of the unit or a breaker has tripped. Which one depends on exactly which kind of vacuum you own. Whatever has happened, you can replace a fuse or reset the breaker on a vacuum cleaner in a matter of minutes -- providing you happen to have a spare fuse lying around.
Unplug your vacuum cleaner and allow it a few seconds to cool down if it stopped working during use.
Remove the utility panel on your vacuum cleaner, using a screwdriver if needed. This panel is typically located on the base of the device, behind the bag or dust container.
Flip the breaker switch back into the "On" position, if applicable. Your vacuum cleaner will begin to work again.
Pull out the blown fuse and set it aside. Insert a new fuse into the same compartment. Your vacuum cleaner will now work again. If you have no idea what type of fuse your vacuum takes, either look in the instruction manual or take the blown fuse to a hardware store and purchase an identical replacement.