Probably a hard drive issue, usually that comes up when it doesn't know which drive to boot from so it might not be seated properly. Or, you might just need to select the drive if there are options appearing on that screen for you to choose from. If there is nothing to select and you feel comfortable with tinkering, I'd disconnect it from power, shut it down, and open it up. Check that all your RAM is properly seated and the hard drive is connected properly. Possibly some cable came out a bit if the device fell or was knocked around a bit. If none of that is an issue, or you don't feel comfortable checking it out, take it into a repair shop and have them check into it.