I've got vertical lines on my iMac 27" screen

"I know this is a very old thread but I believe I have solved the mystery. I purchased a used 27 iMac 5k with 3 black lines on the right hoping I could fix it. I tried everything to figure out why it was bad, GPU, cables, cable connectors, etc. I've also read every question on this topic on this site. It was not until I removed the metal shield on the top rear of the LCD that I saw that it had several cable ribbons from the long PCB connected to the screen. At first I thought the leads were bad, but upon closer inspection I noticed three of the ribbon cables were cut. 3 black lines on the right. 3 ribbon cables cut on the right. It appears that when the last person tried to get into this, they may have used a sharp blade or razor to cut the adhesive. In doing so they sliced too deep and cut into the ribbons! I don't know if the ribbons can be replaced or the rear PCB. I have never seen it sold anywhere and the soldering is so fine it can't be done by hand. :(

See pics:

https://imgur.com/a/31kMq9I"

"The golden rules, when taking the display off:

Never go deeper, with the cutting tool, than 7.5 millimiters (al around the screen).Never pry (the cutting tool should always be parallel to the screen glass).You should cut the ribon in every place, all around the screen.Once all the ribon is cut, put some tape on top of the screen, to avoid it falling.Work on a soft surface, like above towels or something similar, just in case the screen falls.

And, finally, whenever posible, work with the machine lying down (and not upright), as you will reduce the chances of the screen falling off."

"Is this the same issue?

thx!!!!"