I ordered 2 of these. The first one I set up, connected and used an extension cord I had to buy to get the lights to turn on.  Decorated the tree, then set up the 2nd one. As soon as the pieces were connected - the lights turned on!!  Apparently my first tree was defective, but I had already decorated it. The instructions sent with the tree did not inform me that it should have turned on with the connection of the 2 sections.
Be sure to test your purchase.