Folks, I have a Dell 11-3153 2 in 1 laptop.  On startup the Dell Logo appears and goes away with a continuous black screen.  Has power (caps lock indicates power).  Totally unresponsive except to power down.  Powered down multiple times, unresponsive to F2 or F8 or F12 commands.  External monitor indicates black screen also.  Performed hard reset, no luck. Any thoughts how to resolve?