@evgeniylarin you are correct. This is a failed LCD display. What you have is that one segment of the vertical drivers (Source drivers) CoF (Chip on Film) has failed. There is really no fixing it unless you have special machines and skills to do so. The machine will cost a multitude of what a screen replacement will cost you. A display cable can't do this type of error. It will not fail a particular segment the way yours has failed. Replacing the screen will be the right thing.
To work on your computer use the [document|42005]. Page 92 will tell you what you need to do to replace the LCD