I've got a late 2008 version of the MacBook Pro. For some weeks ago, I replaced the screen, and everything seemed to work out fine. But when I try to start it up now, the fans and CD-drive runs, but the screen stays black. I tried to connect it to my Samsung TV with HDMI. When the Mac was turned off, the tv said "No cable connected".When I turned it on, the samsung-screen turned entirely black for a second, but then i turned to "No signal". I even tried to close the screen on the mac at startup (i've heard that doing so will make the mac believe it's a desktop pc), but still the same happens. I can neither boot it in single user mode, cd-mode nor disc mode, so i'm a bit stuck. And I suppose I broke the warranty by replacing the screen. Any ideas of how I can solve this problem?