Why is my computer screen not working properly after every connection is done?

I had slightly different situation that is I recently opened up my computer because overheating was triggering the computer to shut down. When I was doing that I noticed 4 small electrical connectors connecting the motherboard to the top portion of the computer where the key board and the screen are not working. So, if your screen was working properly before, it could be simply be a reason that the screen's Miniature electrical connector has been disconnected by mistake. It is not hard to disconnect one or more of these Miniature connectors if while fixing or cleaning the fan, one has lifted the top portion of the computer just a bit too much. Again if your screen was previously working properly, it could be that a Miniature connector is no longer connected.