DisplayPort LVDs Cable 923-0308 for iMac 27"

In connection to a problem without yet a solution following this link No backlight after adding SSD drive I'm trying to find out if there is something left i can do. So long story short, after changing twice the motherboard, twice the LCD, i still don't have backlight on my iMac. Ruling out every option, I'm searching to buy the LVDS cable, or the DisplayPort eDP cable that connects the LCD with the motherboard (considering the backlights are powered with another cable and cannot be removed from the LCD). I was searching online what did this cable transmit and i stumbled on the eDP version 1.4, which this iMac has, which says that it has a regional backlight control. So, does this cable also command the backlight driver on the motherboard to switch on the LEDs on the LCD?