The cable you refer to in the image is the WiFi antenna…there is no “voltage/current” going through this that could cause any damage as far as I’m aware. Is there a brun mark on the back of the LCD that corresponds to the black spot? You’re LCD problem may just be coincidental to the antenna issue.
It is rather hard to see the spot on the image. Normally, “pressure marks” are white, I can’t say I have ever seen a dark spot in the middle of the screen. Still, I would leave the screen laying only loosely on the frame to see if the spot goes away. Otherwise, leaving the screen on full intensity for a day or two might be beneficial.