One side of the laptop screen is dimmer than the other side. Adjusting the screen brightness doesn’t help.
Backlight lamp failure.
Possible troubleshooting steps and repair solution:
Most likely this problem is related to the backlight lamp inside the LCD screen. Apparently, the backlight lamp is getting old, and stars failing.
If that’s the case, you’ll have to replace the backlight lamp with a new one which is not easy and should be done only by an experienced technician. If you’ve never done it before, you’d better to replace the whole LCD screen.