The laptop has a transparent vertical stripe on the screen running from top to bottom. You still can see the image behind the stripe, but it’s not as bright as image on the rest of the screen.
LCD screen failure.
This is the LCD screen related failure. This problem cannot be repaired at home. If you have a transparent vertical stripe on the screen, you’ll have to replace it with a new LCD screen or use as is.
Alternatively, you can use your laptop with an external monitor. The external picture will not have this stripe.