MacBook Pro A1708 No image repair

Problem description
When the MacBook does turn on but there is no image on the LCD. Backlight may be present but the screen is black

Symptoms

 * No image on LCD

Solution
Check the LCD cable and the connector on both the screen side and the logic board side. The backlight power line is right next to the eDP data line for the image. Any minor corrosion here results in 30 volts or more going to the CPU data line. This we have no solution for since replacing the CPU isn't economically viable.

It can be a bad GPU inside the CPU, which we have no solution for.