I'm using Acer external monitor connected to Dell Inspiron E1405 laptop. Recently I'm facing trouble to bring back the image from external monitor to Laptop. When I press <Fn> <F8> key the image disappears on external monitor but not appears on laptop screen. Some times I can see the image on laptop screen with very very dull lighting, not at all clear. Could anybody help me regarding this?
It looks like you have a hardware problem with "backlight" or the "inverter" on the laptop screen. Use the Dell Diagnostic program to test the PC. Hit F12 during a reboot and select "Diagnostics" and follow instructions from there. I hope the laptop is still under warranty. Good Luck