Acer 5720 Blank Screen

Hi,
my daughter has an Acer 5720 Laptop which has mysteriously developed a blank screen.

She swears she didn’t drop it, and the laptop doesn’t appear to be damaged in anyway.

I’ve tried rebooting it and pressing f5/f6 but nothing.

I attached the laptop to an external monitor, and have had limited success – the graphics appear on the monitor (the laptop screen remained blank), the password was entered, the boot sequence begins, and I can hear the drive whirring away in the background, but nothing comes on the screen again.

Can anyone help – but not by suggesting I download and run a repair, remember the screen is blank so I can’t access anything to download it 😉

Thanks
Les