Question : Problem: Backlight shorts in and out

Hello,

 

I am working on a Dell D505 laptop. The display is dark when operating.  When I put pressure on a small area near the power button the display will come to life with the normal backlight display.  I have noticed when I put apply some light pressure on the left side of the power buton PCB (pushing it ever so slightly to the left) I will get the full normal display otherwise I get just a dark display.  I have taken the laptop completely apart and cleaned underneath the motherboard.  I have not noticed anything unusual that would be causing a short. What could be causing this problem? I appreciate any and all help with this problem.

Answer : Problem: Backlight shorts in and out

Yes, you have most definitely narrowed it down using your monitor troubleshooting method.
The service manual can be found here for your D505.
http://nokomis.k12.il.us/unit-office/technology/downloads/sm.exe/view
(As usual, please take precautions when downloading and scan the file prior to opening.)
David