Someone on another board recommended to test the power coming into the logic board, to see if the power supply is provided the necessary 23~25.3V required. Using my multimeter, I confirmed the logic board is receiving the correct power. Now I suspect it's something related to cold solder joints, I just don't know what part of the logic board to concentrate on. I looked it over, but I don't have access to an X-ray type machine to examine cold solder joints. Any idea where I should just blindly fix the solder points to fix the backlight issue?