I would suggest you to follow the below mentioned steps which could fix the issue:
•Push monitor Auto Adjust button.
•Perform monitor reset.
•Boot up in the "safe mode".
•Ensure monitor is in proper video mode.
•Adjust the resolution.
•If possible try connecting another monitor and check if the video is fine on another monitor or not.
Kindly revert and let us know the status.
Thanks & Regards