T23 display is BOTH yellowish and bluish

[rardhian]

Hi everyone, I am a Thinkpad newcomer and also Thinkpads.com newcomer

I've just recently purchased a used refurbish T23, and after several hours toying with it, I found that the display is inaccurate. At high luminosity (colors close to white and white itself), it will display slight yellowish white. At lower luminosity (greys), it will display bluish grey. The yellowish is slight but the bluish is very noticable, i.e. you'll never be able to see grey color. Those colorings is slighter if you set the brightness to maximum, but very noticable if the brightness is set to minimum.

After having some quick googling, I found a T43 review at NotebookReviews which says:

...The whites on this screen are also not pure white but rather have a very slight tint of yellow, it's not uncommon to find that an LCD presents whites with either a very slight yellowish or bluish hue.

Hmm... so what should I do now? Is it really the `backlight' LCD thing? I'm really interested to open the notebook

I know it sounds possible to correct it with some gamma correction values, but I doubt it since; 1) it won't work if the LCD hardware is the cause, you'll never get white pixel. 2) it will require gamma correction which is adjustable at several illumination value (haven't heard that?). The gamma curve should made like an 'S' letter...

And one more thing. The brightness is also uneven. It is brighter at the bottom, and darker at the top part of the screen. So, no matter at which angle you look at the screen, you will see brighter blue for the Windows taskbar, and darker blue for title bar on maximized windows. It is possible to fix it by curving the screen horizontally, I guess.. But I would like to know if it's because of my refurbish condition or it's Thinkpads in general.

Haven't got any other Thinkpad to compare

[Inky]

My own experience with a yellowish LCD might be helpful to you, even though it was with a desktop LCD.

I bought a 22" LCD flat panel display and it had a strong yellowish tint.

There is one useful test I was able to perform on it, but I'm not sure how you could do this with a laptop LCD.

I disconnected the data cable from the monitor, and when I do that there's a thing built into the monitor that makes a white box float across the screen containing the message "No Signal".

Tech support told me to pay attention to the color of that white box. If it looked perfectly white, then it meant the yellowish tint was coming from the signal sent by the graphics card. But if it was STILL yellowish after I disconnected the data cable, then that would prove it was the monitor.

It remained yellowish after I unplugged the data cable, so I knew it was the LCD.

Step two: I took a 10x lupe (one of those small cup shaped magnifyiers used for looking at slides.) and I looked at the screen using the lupe. What I saw was incredibly revealing. The screen was made up of thousands of tiny ribbons--red ribbons, blue ribbons, and green ones. And while some colors (such as the red ribbons) were perfectly straight, some of them (the blue ones if I recall) had become crinkled with the end result being that the distribution of color on the screen had been altered on such a fundamental structural level that there was no point trying to compensate with software adjustments to gamma values.

I got another one of the exact same LCD, and for a while I had them both side by side on my desk, and the new one looked slightly bluish, but it only seemed bluish by comparison--because my eyes had adjusted to the yellowish tint of the first one.

When I looked at the new (seemingly bluish) screen using my 10x lupe, I could see that all the color "ribbons" were absolutely, perfectly straight. Under the magnifying glass the new one looked dramatically different from the yellowish screen where some of the color "ribbons" were wavy and messed up. So I chose to keep the new one and after a while it no longer seemed bluish, just white.

I don't know if there's anyway for you to do the first test on a laptop, but I recommend looking at your screen (and others) with a 10x lupe.

Hope that helps.

-Inky

[bhtooefr]

As for the uneven backlight, I've got that on my X21, and my old Toshiba. Basically, I think it's either the diffuser's not quite on right, or the backlight is wearing out. It's barely noticeable on this, but it's VERY noticeable on the Toshiba.

[rardhian]

Wow, thanks! That was a great explanation. Now before I find a 10x lup, I suppose I should find another Thinkpad to compare...

Btw, I've made a simple diagram showing what the yellowish and bluish looked like. As you can see, it's not always yellowish, but also bluish at mid-range illumination.

http://students.if.itb.ac.id/~if23053/i ... bluish.jpg

Thanks for replying guys, since this is a refurbish notebook, I don't mind at all about the problem. For now, setting the brightness to its maximum greatly reduces the effect. The only thing that makes me curious is that it may also happens to new displays. Now I'll be very careful about displays!

Edited by Moderator: Links, not images, without a warning in the Subject line.

[bhtooefr]

Your diagram isn't showing up. Most likely, a mod deleted it. Post a link to it, and we'll be able to see it.

[rardhian]

Hey... why did the mod delete the diagram? I made the diagram. Or is it illegal to post picture with img tag?

Anyway, I think I found why the whole thing happened, bhtooefr is right. It might be that the backlight bulb has become fainter and turned yellow because of aging. Meanwhile, I tried to correct with the gamma settings, thus resulting bluish grey (or the display itself might be natively bluish).

The store from where I bought it has offered me another T23 for a replacement. But I don't know, considering it is *also* T23 and might be at the same age, sooner or later the backlight will become yellow too. I really think backlight replacement is best but unfortunately they didn't have any of those and probably will never have one. Maybe I'll take my money back as they also offer money back guarantee.

Then I'll think a way to get a free *real* Centrino Thinkpad.

[bhtooefr]

Yeah, you're not supposed to use the img tag unless you put a warning in the subject of first post of the thread.

[Ted_E]

[quote="rardhian"]Hi everyone, I am a Thinkpad newcomer and also Thinkpads.com newcomer

I've just recently purchased a used refurbish T23, and after several hours toying with it, I found that the display is inaccurate. At high luminosity (colors close to white and white itself), it will display slight yellowish white. At lower luminosity (greys), it will display bluish grey. The yellowish is slight but the bluish is very noticable, i.e. you'll never be able to see grey color. Those colorings is slighter if you set the brightness to maximum, but very noticable if the brightness is set to minimum. ...
</quote>

I also have a refurbished T23. I purchased mine from IBM. I do not seem to have this problem so I suggest you might want to go back to the store and check out another machine. Here is a test you can do on your machine: Go to
http://www.pmview.com/download.html
download the windows version and install it. Run it and click
File=>New=>image
set the size to (say) 1024x768
Now click
Color=>Convert to=>Indexed 16 Color=>OK
Now click
Color=>Edit pallette
Push the three sliders right to the top and click OK
Press <F3>
This will give you a full screen image of the most reliably pure white of any photo program I've tried. Hold up a piece of photo quality printer paper beside your screen and compare. Get back to a window by pressing <F3> again.

On my machine, in a room well lit by daylight, the screen color is essentially the same as the paper but not quite as bright.

BTW, you might want to buy PMView. It's a good program and cheap.

Ted

[rardhian]

I didn't bought it from IBM, so I guess it's not an "IBM standards compliant" refurbished one

Anyway, today I'm going to the shop for replacement. Let's see what happens next