My 2011 Macbook Pro 17 has hit a rather stark functionality problem in that the screen will not turn on any more (is just black). I can still hear the chime when I press the power button, but I'm struggling to ascertain whether the rest of the computer is still functioning and it is just a screen issue. I plugged a mini display port->HDMI adaptor into the thunderbolt port and hooked it up to my computer monitor, but so far nothing. The fans are spinning and I get the chime, but that's about it. Is there any way to check if it's just the screen that has died? Thanks in advance.