T21 screen: white cloud-like spots

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Pentagonees · #1 Post by **Pentagonees** » Thu Aug 16, 2007 1:14 pm

I recently bought a second hand T21. It was very reasonably priced, even though it has a minor flaw.

The minor flaw:
The 13.3" screen shows some white spots. They are a kind of "see through" white, since they do not cover up anything. They don't look like dead or stuck pixels, since they are white all the time. They are best visible on white/light backgrounds. There seems to be very little information available concerning these "stains".

Does anyone know:
1. What they are?
2. If they can be removed (or at least made less visible)?
3. If there is a possibility that these spots could spread/multiply? I'm thinking of upgrading the CPU and RAM, but i'm reluctant to do so if there's a possibility that the screen goes totally bad.

Pic of the screen can be seen here: http://img230.imageshack.us/my.php?imag ... 835sf5.jpg

Cheers!

Eric Giles · #2 Post by **Eric Giles** » Thu Aug 16, 2007 1:33 pm

Those white spots are generally caused by excessive pressure that has been applied to the screen. Not sure which part of the LCD it 'damages' to cause that-I think it is the polarizer-but unfortunately there is nothing you can do to fix it. It is slightly annoying, but the spots should not spread, unless too much pressure is applied to the screen (such as putting something heavy on top of the lid, etc).

Only fix is a replacement screen that is guaranteed not to have the white spots. If you can deal with the spots, then just let them go until the backlight or the LCD cable on that 13.3" screen fails!

Pentagonees · #3 Post by **Pentagonees** » Thu Aug 16, 2007 3:00 pm

I think you're right about the excessive force. Found a website, concerning the same problem with Apple Powerbooks, a couple of years ago: http://www.macfixit.com/staticpages/ind ... 4074841479

There it says:

Though heat was identified as a possible cause originally, most experts now agree that there is some sort of unnecessary pressure on the screen that is causing the spots.

As long as it won't get any worse I'm fine with it (I will be using my T21 alongside my iBook G4). I'll upgrade the T21's CPU to a 900 Mhz and RAM to 512mb (I already swapped the HD for a 40gig 5400rpm I had lying around).

About the backlight and the LCD cable: are they likely to fail, or just as likely as for any laptop, 5+ years old?

Eric Giles · #4 Post by **Eric Giles** » Thu Aug 16, 2007 3:13 pm

Pentagonees wrote:About the backlight and the LCD cable: are they likely to fail, or just as likely as for any laptop, 5+ years old?

Well this is coming from my personal experience with the T2x series and their 13.3" screens, but almost everyone of them has failed due to the backlight dying or the LCD cable going bad-sometimes both issues occur on the same machine. The 14.1" screens seem to be more durable or longer lasting in this regard. Not to say there aren't 13.3" screens that won't last just as long (I have seen that too), it's just not as common.

But don't worry about all of that-just enjoy your 'new' T21!

Pentagonees · #5 Post by **Pentagonees** » Thu Aug 16, 2007 3:29 pm

Will do! Thanks!

#6 Post by **rkawakami** » Thu Aug 16, 2007 3:36 pm

My experience is a little different in that regard, but as I buy mostly 14.1" T2x parts/repair machines then I'm obviously skewed in this data....

I have several (many, depending upon your definition

) 14.1" T23 LCDs with pressure spots. Some are hardly noticeable (but I know they're there) to major. The only 13.3" T2x system I have has a failing backlight (infamous red turn-on problem). They haven't gotten any worse with age or use as far as I can tell, but the previous suggestion about replacement is the only way to "cure" the defect.

joester · #7 Post by **joester** » Thu Aug 16, 2007 5:32 pm

If you're gutsy enough, you can swap the polarizer with a good one from another dead lcd of equal or larger size. Might have to trim it, and a papercutter is best to avoid bending the polarizer.
ANY scratches on the surface will stand out in the finished product.
It requires COMPLETE disassembly of the LCD itself, and EXTREME caution with the electrical connections.
I was invloved with a rebuilding attempt at work to see if it would prove to be economical to offer the service. It is possible to do, but there are SEVERE cleanliness issues to consider.
You almost need a clean room for the job, and fingerprints stand out worse than the whitespots.

Pentagonees · #8 Post by **Pentagonees** » Fri Aug 17, 2007 5:55 am

That's sounds like something only the "expert" should do (which I, obviously, am not)! I located a 13.3" screen, exact same make and model as the T21's, as well as an inverter. Maybe I should buy them, just in case...

jamerslong · #9 Post by **jamerslong** » Fri Aug 17, 2007 11:10 am

well, Takin my Experiences with Dissasembling the LCD's i can say that with a little research Replacing the Polarizer is not too difficult, Lumenlab.com would be a great source for information.

BUT, i highly doubt that this defect is the Polarizer but is more likely the antiglare, which is also an easy fix "IF" the LCD can be properlly "Stripped" and Reaplied.

I tell you what, if anyone has an LCD screen (model dosent matter) they can send me that suffers from this problem and they dont need or want back i will dissasemble it. It dosent matter if it is inop as long as the LCD is not CRACKED

joester · #10 Post by **joester** » Fri Aug 17, 2007 7:26 pm

Pentagonees wrote:Maybe I should buy them, just in case...

If the replacement parts are affordable to you, I would grab them. Having spares, the originals will never die.

Worse comes to worse, you are prepared.

al7kz · #11 Post by **al7kz** » Fri Aug 17, 2007 9:48 pm

delete

T21 screen: white cloud-like spots

T21 screen: white cloud-like spots

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