Well, Wifi is the most common problem…if that’s eliminated, the next thing to check is the cable connections for the lid cables. Make sure all of the connectors shown below are closed and flat.
(Just read through the third check at this link for what to look for. If that isn’t it, you’ll need to let support take a look at the logs for the machine. Be sure to tell them which machine it is (name) if you have more than one, so they can pull the correct logs.) Also helps a lot to give them the time and time zone of the problem print.