My retina screen has a white stain inside.
I cleaned my screen with a damp cloth, and this stain showed up. Why is that?
Liquid has leaked behind the screen and stained the backlight sheets. If you're lucky it might dry out, but in most cases it will not; so you are either stuck with it or you can replace the whole assembly
The same thing happened to me when I was cleaning off the residue of the peeling antiglare coating with various solvents (thank you, Apple)… Anyway, it is hot now so I hope it will dry on its own, but:
If I take off the display assembly and peel off part of the rubber bezel, how safe it is to ‘blow-dry’ the affected corner? Would it just cause more damage if I blow hot air over the sheets?