No screen after opening laptop

Since some weeks ago, artifacts appeared on my screen sometimes, which were usually fixed by shaking the laptop and/or opening and closing the lid fast multiple times.
No problems with external monitor, so I thought it could be the lcd cable was loose. Since I was planning to repaste, I didnt try to fix it.

But today the paste arrived, and besides doing the paste job, I disconnected the lcd cable from the motherboard, cleaned it with isopropyl, and connected again (yes, I opened and closed the small black clip).
No Image, so I did again. External monitor works fine. So I cleaned once again and tried, but still black screen.
So I thought the loose part maybe was the connector between the cable and the screen itself, so I disconnected and connected again, but still black screen.

What can it be? The cable itself?

 

Yep. If the connections at either end are good, it's probably the cable. They are very thin wires with very thin insulation that can easily fray or break over time from the movement that occurs with every lid open and close motion. Sometimes you can twist them 360 degrees to re-engage them... but that's a temporary fix if it works.

Check it's not getting pinched in the hinge, but consider ordering a replacement now before it completely borks.

 

Yesterday I found out the connector had like what seems some scracthes:

Spoiler: pic

I dunno if theyre scracthes or taints of LM from the previous owner...

Is there any guide to change the cable itself? I only find guides on how to change the screen

 

So I changed the cable, but still no image. What else can it be?