Chances are that a wire has broken inside the cable at the plug end - a very common fault caused by tugging on the cable. An unseen fault.
It will not take long or cost much to cut away the plug together with a few inches of cable and to fit a new plug.
My guess based on experience is that by doing this you will restore Henry back to life. I have repaired perhaps 20 vacuums this way.
Good Luck..., November 2015
