Hi ladybeethatsme,
Please run the LCD BIST test in the system to check the LCD is working as designed. Follow the steps below.
Turn the computer off >restart the computer
At the Dell logo screen, start tapping the F12 key a few times until you see the One Time Boot Menu appear.
At the one time boot menu press the down arrow key to highlight Diagnostic, then press Enter to begin the PSA diagnostics.
You will soon see different colors on the screen; at this point please press N which will begin the LCD BIST Test. This test will help us to identify, if there is any issues with the LCD.
The screen will display multiple flashing colors. If you observe any blurry video, distortion and or any lines on your screen, it would mean that the LCD screen may be faulty.
During the test do check whether the vertical lines are appearing? Also connect a known good monitor to the laptop and check if the vertical lines are appearing.
To back up the data you may have to contact the local technician.