Lexmark MS517
Try one or more of the following:
Note: If the printer finds a tray that has the correct size and type of paper, then it feeds from that tray. If the printer cannot find a tray that has the correct size and type of paper, then it prints from the default paper source.
No pick or ‘Load Tray 1 with specified paper’ message appears even when the tray has paper in it? See this article on how to troubleshoot.