I have a laptop which when I turn it on the screen is bright white and you cannot do anything on it. The screen is white all the way through the BIOS setup and POST so you cannot enter the BIOS or boot from CD.
However if I plug in an external display using a docking station the external display functions correctly and allows me to login to Windows and control the OS but the laptop Display doesn't work still and remains white.
I have tried updating the Drivers for the display and also updating the Graphics card drivers and I am still getting the same issue.
I have also tried adjusting the brightness of the display using the keyboard shortcuts FN + Up\Down Arrow.
Finally the laptop is a Dell Latitude E5420 running Windows 7.
Has anyone seen this before or Know what could cause this issue?