What are the white spot on my Laptop LCD screen?

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Today, I've cleaned my laptop screen and noticed white spot that can be seen behind a white background pixels. There are about 3 or 4 of these little spot on the right and left side of screen. It seems like they are formed when something had hit with screen. Any idea what can they be, if they are permanent?

user103231

Posted 2012-05-04T02:05:34.260

Reputation: 3

Answers

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Well... with LCD, white isn't so much a color as it is the absence of any filtering in the liquid crystal, allowing just the white background to reflect light through. That said, you can see the white spots behind white background pixels. What happens when there is a color over that spot. Do you still see some kind of mark there? Are you sure it is not something on the screen (sneeze debris, etc) that didn't come off when you cleaned it?

If they stay white regardless of the color there, but only show when the screen is on, then they are most likely now dead pixels.

But it is really hard to mark up the background reflector that is behind the LCD panel.

Bon Gart

Posted 2012-05-04T02:05:34.260

Reputation: 12 574

I've just tested it behind pure red, green, blue background and yes they are there. But behind a black background they cannot be seen, it is just black. – user103231 – 2012-05-04T02:31:23.870

The white reflector behind an LCD panel is typically hard plastic, albeit thin plastic... as opposed to a simple paper that could be torn or marked up due to a gentle impact. You have definitely determined it is neither dead pixels nor in front of the LCD layer. It could be something between the last layer of the LCD panel and the reflector. Not that I'd advocate you take apart the LCD panel (I've done this many times tho), but can you localize when the damage first appeared? – Bon Gart – 2012-05-04T02:36:58.063

Yes, I have marked these white spot with red in this sample where they appear on my screen.

– user103231 – 2012-05-04T02:51:02.567

How about when? They almost appear to be hand damage... as if you (or someone) was holding the laptop when it was closed, and their fingers or edges of their palms were at those points on the lid. The edges of laptop LCDs are typically sealed with foil tape, and the panels aren't known to be loosely assembled, but excessive screen twist (opening the lid from one corner repeatedly) can separate the layers of an LCD, and theoretically allow debris between the reflector and last layer, provided the foil tape was also damaged, but that's a stretch. – Bon Gart – 2012-05-04T02:55:55.087

I guess it could be about an year ago when I used to take my laptop out with me and I remember when somebody tried to grab it from screen. But today it is the first time I noticed them. You have to look closely in that area to able to notice them. Is there a chance that it will become more damaged by just little pressure? – user103231 – 2012-05-04T03:12:22.057

If pressure is what caused the spots in the first place, then yes, any additional pressure will make the more pronounced. – Bon Gart – 2012-05-04T03:14:13.623

Can other screen laptops such as TFT or LED be damaged in this way If I'm going to buy a new one? – user103231 – 2012-05-04T03:21:09.313

TFT is just a variant of LCD. Most LED laptop displays are LCD with LED backlight instead of CCFL. There are some newer OLED displays, like this Samsung http://www.engadget.com/2010/01/07/samsungs-14-inch-transparent-oled-laptop-video/ but at the moment a true LED replacement screen would be far too expensive. Otherwise, any screen could, in theory, be damaged this way. The design of the laptop is more a concern.

– Bon Gart – 2012-05-04T03:33:36.713