There was a (common cause) power arc during the swap (while running the vacuum).
The fuse located under the grey clipped-on plate of the canister is blown. The fuse is soldered-on the board and would need to be changed (board or fuse). Not "user friendly" zone. Warranty? Smart if they designed a breaker button instead of a fuse here...
Rick

Are there seperate switches for the powerhead and the canister.take the powerhead off and try it again .if it works then there is something wrong with the the powerhead