Hello techs,
I have an Asus X751LKD motherboard and in HD screen OK, in FHD lost vertical lines.
I was trying with reballing a GPU, same issue.
Any help?

Photo ?
original LCD is FHD ? type LCD LVDS 40pin or eDP 30pin ?
if 40 pin,make a measurement on the lines of LVDS?it must be the same value!

I have same notebook, I try with other display+lcd cable, same issue. (17.3" FHD 40pin, no eDP 30pin)
I have problem with motherboard. I cant find the problem with second channel in display.
I attached photo.

what about measurement on each 8 pair's lvds? 16(pins)/
make big photo of motherboard(both sides)/
maybe your have multiplex like rt2136 ??

I have the RTD2136R.
Attached photos (not good pics, I'll try with other camera) and datasheet of RTD2136R.

i think that problem with RTD2136!
measure resistance on LVDS lines ?ALL of this 16 pins must be the same value.

26 - 27 - 28 pins are dif resistance.
I'll try to change the RTD. And see...

Thank you, I'll inform you...