Yellow fog at side/bottom of screen

Archived from groups: comp.sys.laptops (More info?)

___X wrote:
> Has anyone seen anything like this before?:
>
> Yellow-orange fog at the sides or bottom of the laptop LCD screen,
> with possible bluish discoloration toward the center. In this case,
> the yellow-orange haze shifts position according to gravity: if the
> laptop is stored on its side, the fog moves toward the bottom (the
> side it's resting on).
>
> Repair techs say they haven't seen it, but I've encountered it on
> two different laptops. Have you seen anything similar? Any idea of
> the cause?
>
> (This particular laptop is a Toshiba M35-S456, with TruBrite LCD
> screen.)

Do others visually confirm what you see? The reason I ask is that the
optical properties of an LCD are different depending on the point of
view, and for a consistent apparition depending only on the rotation of
the screen indicates to me it is possibly an artifact of the viewer's
eyes. This could be due to a slight polarization of the viewer's
glasses - optical coating for glare reduction, etc., refractive effects
of the lenses/progressive "bifocal" lenses, material of contruction
(glass/polycarbonate).

Q

Archived from groups: comp.sys.laptops (More info?)

___X wrote:
> On Tue, 26 Jul 2005 05:58:21 -0600, "Quaoar" <quaoar@tenthplanet.net>
> wrote:
>
>> ___X wrote:
>>> Has anyone seen anything like this before?:
>>>
>>> Yellow-orange fog at the sides or bottom of the laptop LCD screen,
>>> with possible bluish discoloration toward the center. In this case,
>>> the yellow-orange haze shifts position according to gravity: if the
>>> laptop is stored on its side, the fog moves toward the bottom (the
>>> side it's resting on).
>>>
>>> Repair techs say they haven't seen it, but I've encountered it on
>>> two different laptops. Have you seen anything similar? Any idea of
>>> the cause?
>>>
>>> (This particular laptop is a Toshiba M35-S456, with TruBrite LCD
>>> screen.)
>>
>> Do others visually confirm what you see? The reason I ask is that
>> the optical properties of an LCD are different depending on the
>> point of view, and for a consistent apparition depending only on the
>> rotation of the screen indicates to me it is possibly an artifact of
>> the viewer's eyes. This could be due to a slight polarization of
>> the viewer's glasses - optical coating for glare reduction, etc.,
>> refractive effects of the lenses/progressive "bifocal" lenses,
>> material of contruction (glass/polycarbonate).
>>
>> Q
>
> Hah! I take it you haven't seen this before. <g>
>
> Yes, it's not a subtle effect. Visible straight on. The first screen
> was no longer readable, even at a dead-on angle.
>
> This one was confirmed defective within about 2 seconds by Toshiba
> warrantee center. It's being replaced.
>
> I'm wondering about the cause. I would like to prevent it from
> happening again, especially out of warranty. I thought the first may
> be due to overheating, but that would definitely not be the case with
> the second. Possible bad batch of displays, as they were roughly the
> same vintage.

I wonder, since this is a real effect, if it is oxidation of plasticizer
in the plastic layer, maybe due to heat?

Q