C769us Dim LCD Display

I'm attempting to fix a dim display for my Compaq Presario C769us Notebook and have hit a snag on finding the possible cause.

A quick background on the issue:
The LCD display would originally go dim at certain points when the notebook lid was open at extended angles. The problem got worse as time went along and only allowed for a bright display when the laptop lid was barely open. Now the display is dim at all times.
If I shine a flashlight on the screen I can see it startup and go into windows without any problems.
If I connect the laptop to an external montior it displays perfectly fine.
The problem exists while on battery on plugged in to a power outlet.
Adjusting the brightness through the Fn F7/F8 key combinations has no effect on the display.

I have progressively replaced the inverter board, then the LCD screen, and then the LCD video cable with new fully compatible versions of each and still have the same dim display at all times.

My next step is to rule out a faulty lid actuator switch, but I can't seem to find it, or even confirmation that one exists on the C769us model. I have seen similar posts referencing a magnetic lid switch, but again, I don't know if the C769us model uses one. The assembly manual for the C769us model does not reference a lid switch at all.

If anyone can point me to the exact location of the lid acuator switch, or the documentaiton to find it I would be most appreciative. Also, if anyone has any other suggetions on the potential cause of my dim display, please feel free to share.

Thanks.