My acer laptop screen has recently stopped working. I'm currently using an external monitor since the screen is so dark it's almost impossible to see anything. I read on another post that this is commonly due the to backlight burning out, but first to check the backlight hasn't been toggled off. So i've hit Fn and F6 to toggle the backlight and it will flick on for a few seconds but then goes dark again...this suggests to me its not a burnt out backlight but some other problem...any ideas??