Start with a screen diagnostic - hold D through powerup.  Do the test screens show the same fault?   Yes:  Replace the display panel. No:  the problem is elsewhere (could be the cable, or could be a driver or GPU problem).    
I bought the laptop from local vendor in 2021 April, until recently display worked perfectly fine, but two days ago suddenly display starts to stutter. [URL]   Please help me here, to resolve this.
Dell Inspiron 15 2000 Display trembling and stuttering.