R710 Display problem

Hi, was wondering if some knowledgable people might help me diagnose my laptop.
full model number is R710-AS06UK

Symptoms are:
-display backlight appears to be fine but never shows any picture

-laptop is starting up and can log on fine(based on the vista sounds I hear)

-I have tried to connect various other displays to the vga port and the hdmi port but haven't managed to get them to show anything, i'm not really sure what(if any) steps need to be taken for it to use the secondary output though...


I tried opening it up to look for obvious connection faults under intruction from a service manual but couldnt for the life of me figure out how to get the casing above the keyboard off(where the lcd cable would be).

If anyone can tell me the likely problem that would be greatly appreciated

 

Pressing Fn + F4 will step through the internal / external display options. It is best to connect the external display before booting to ensure that the display is detected.

I have known display problems because the connector between display and mainboard has worked loose. This may be under the keyboard which is relatively easy to remove. Sometimes disconnecting and reconnecting can fix the problem. Dismantling the rest of the computer can be challenging: Remove all screws and then carefully prise apart at the seams.

John