Dell Inspiron 7520 15R SE Screen Brightness Issue

My laptop's screen no longer functions beyond a very dim setting. To see the screen is incredibly hard and requires much eye strain.

The Fn F4/F5 keys do nothing to alter the brightness and neither does manually sliding the brightness bar in control panel and the brightness slider within the Intel video settings app.

If I plug in an HDTV using the HDMI slot then the TV screen display is clear and functions normally.

Around the time my laptop screen stopped working correctly I also started to get 'Appcrashes' from basic programs such as firefox, itunes, skype etc.

Uninstalling and reinstalling my video drivers seemed to resolve the software crashes but had no impact on the screen's brightness.

Could a hardware fault cause drivers to play up?

Interestingly, Installing the program  'Desktop Lighter' which over-rides my basic brightness function does boost both the plugged in TV and the laptop screen's brightness, however still not adequately to be able to clearly view the laptop screen. 

I've also tried updating QuickFix and Bios and altering my battery settings, but to no avail.

Any help would be much appreciated, although I suspect this is probably a hardware fault and I'll have to ring dell up about it for parts. (Laptop is still in warranty.)

Thanks!