M11x R2 keyboard backlight issue

Hi guys, I have my M11x R2 for almost 6 years, and a year ago I drop it for the first time by accident, the keyboard backlight started to flicker sometimes, then after some weeks it went all off (only the light, all the keys still work).
The front "grill" lights work normally, the Alienware logo on the front of the screen is faulty due stupid repair done by a repair shop, but the keyboard lights were working normally untill the drop.
My question is: is it a motherboard chip issue or just a keyboard issue, if it's only a keyboard issue I already know where to find a replacement, but if it is something more internal as a chip in the motherboard then I'm out of luck.

 

It may just be the ribbon cable for the backlight got dislodged when you dropped it You need to remove the keyboard to check this. There are two cables coming out of the keyboard. The backlight cable is the thinner brown one. It is locked in place and should not come out easily, but a drop may dislodge it.

As for the screen logo backlight, there are several cables that come out of the screen, 1) the LCD and webcam cable which attaches to the motherboard, 2) The WLAN/WWAN antenna wires (either 2 antennae or 4 depending on display model) , and 3) the LED logo cable. The LED logo cable is attached to the touchpad cover underneath the power button assembly. That cable is probably not plugged in.

Here's the service manual for the M11X:

http://153.127.244.43/pdf/2013-02-01/73768.pdf

 

I think that when I opened it, it was a little loose that thinner one, thanks for the help and information.