Hy

White screen is usually an internal LCD failure -- if you need something more specific, post the full system model number (i.e., Latitude 7430) and whether or not the problem is present at bootup or only on recovery from sleep.

@ejn63​ Dell Latitude E6330 laptop

If it is an issue on bootup as well as from sleep, chances are the screen needs to be replaced.  On a system that's worth about between $30-50 complete and working, you're better off replacing the system with something newer than repairing this one.

@ejn63​ thank you ,I'll do so I was stressed