U3415W, no display

I was using my Dell U3415w monitor this morning when I saw the screen fade from right to left to a black screen.  The monitor is now unable to display anything, but you can see tha backlight come on.  I tried connecting multiple laptops to the HDMI port and the DP port but still only see a black screen.  The monitor menu will not display or is not visible.  I've tried unplugging all cables and power with no effect.  Even with only the power connected the monitor menu will not display, but you can see the backlight illuminate.  Is my monitor dead?  Thanks