I have a problem on my new laptop Dell Insiron 5559. It worked well for some weeks, but now, the integrated screen doesn't work.
The led twinkle white and orange; and the computer seems to work fine except the screen. An external monitor connected by HDMI is working perfectly, but it is "alone": windows doesn't even detect the integrated display.
I also tried some tests procedures:
From the dell support website, every display test is performed on the external monitor.
The tests triggered at start (when pressing Fn + Power) also use the HDMI screen, and detect an error:
Error Code: 0415 Validation Code: 121740 Service Tag: <ADMIN NOTE: Broken link has been removed from this post by Dell>
The strange thing is that when I start the other test procedure (by pressing D + Power at start), it is the integrated display that is used, and shows perfectly the different colors.