Most likely will need to swap out the video card or run a bios flash. Bios flashes are super simple with dell but make sure you know what you are doing as a flash to the bios, if done improperly, will brick the entire machine.
Dell windows 10 (not sure full tittle, bought off streets years ago) screen is flickering purple, green, white & black on startup. Also, making odd sound?
Did you try opening it in safe mode?