I have the same problem. My LCD originally is getting fuzzy on one vertical column on the left side of the screen that was about 2in wide. I thought the lcd was bad. I ordered a new replacement, put that on. Things seem to be fine. Minutes later, this new setup has a similar issue with another column of the screen just left of the center line of the screen about the same width.
I took apart the lcd and try to isolate the problem. plug the old lcd back in, jiggle the cables, pull the cable in and out. At the end, I got the no-backlight now.
I'm suspecting the cable. Hopefully, the motherboard is still in good shape.
Here is my theory, the video run through the left hinge. This area is very heat prone. Apple already replaced the hinges for us. The original one is a plastic one. It fails after a couple of years. The current alloy one is much sturdier. However, I believe the heat has cracked and caused internal damages to the cable. I suspect my original lcd was good. It was only the cable. However, since when cable shorting may cause other unintended and unforeseeable damages to connected component. My recommendation is to stop using the computer as soon as you see any display issue and replace the cable.