Login screen flashes

When I go to login when turning on the computer, the login screen flashes. It only blinks in the username, place for password, and language gaps and desktops, It blinks between black and its original color, any solution?

To help, we’d firstly need to know your release of Lubuntu, and secondly we’ll likely need some details of your video card.

To get details of your video card, I’d suggest using the command

sudo lshw -C video

which will list-hardware of class video.