Do you have a monitor available? You could plug in an external monitor and see if you get a picture. This would then show it was the screen at fault. Certainly contact Acer for help especially if you have extended the warranty.
My son had same problem with Sam-sung NC10. OS XP.
I tried a external monitor and still no signal to use an external monitor on NC10 was to hit the FN and F4 button simultaneously and that switched on the laptop and external monitor. I held them down during boot up.
Found this for the Acer Aspire 9300.
Try the "Fn + key" to make sure you have selected the external monitor and then rebooted the computer?
In order for the laptop to recognize the new monitor it has to be installed and configured.
Usually a reboot with it connected will do the trick. You may also have to play with the Fn keys to select the alternative video source. Hope this helps!