Sony kp57-ws500 changed d board 3 times still has convergance issue

hello fellow techs!
I am in a continous loop with sony where they have sent me 3 d-boards and none of them are working. i keep getting the same issue convergance and in some instances a line in the middle of the screen. I cant help but think I am doing something wrong but i have scoured through this forum and google to find out if i am. looks like i am might just have bad luck or i am breaking these boards?
thanks for the help :)