Unplug the vacuum. Face the front of the vacuum and push the height adjustment lever down. This piece is found on the right side of the vacuum when facing it.
Remove the light hood.
Turn the belt lifter to the left. Move the lock found underneath the light hood over to the left side.
Remove the front piece of the vacuum cleaner to get a better look inside. Turn the belt lifter, at the top of this front piece, to the right until the belt drops down low enough to be visible.
Turn the front piece until you see two latches on the back. Unhook the latches to remove the roller plate.
Remove the roller plate and note which side of the roller the small magnetic strip is on. Then pull the roller out.
Clean the roller of any debris or hair. Check the vacuum belt, and replace the belt if it is cracked, broken or stretched until it has become loose.
Check the fan, located inside the vacuum. See if it spins easily. If not, remove any debris blocking the fan, or replace the fan if it is broken.
Change the vacuum bag. Reassemble the vacuum and turn it on. If there is a still a problem, contact a professional repairman.