LCD dim.....

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ThinkPad · #1 Post by **ThinkPad** » Thu Jan 17, 2008 8:17 pm

After looking at a couple new laptops, their screens seems to be brighter than my 14inch SXGA. Even my XGA T60 is brighter. This is with the computer plugged in at max brightness.

Question, could if be possible that my LCD inverter has slightly worn out over time (5years) I dont remember what the LCD was like new, but i think as time progressed it gradually became dimmer....

ajkula66 · #2 Post by **ajkula66** » Thu Jan 17, 2008 8:25 pm

Every LCD loses brightness over time, and the one you're referring to hasn't been one of the brightest to begin with.

SHoTTa35 · #3 Post by **SHoTTa35** » Thu Jan 17, 2008 8:29 pm

i noticed that like CRAZY with my T42 and T60. I had em both in a dark room and when i waked in the T60 was super bright! They were both on AC power cuz i walked over to the T42 to double check. Surely the T42 is years old but man the T60 was like 3 times brighter, i couldn't even look at it with full brightness, gotta turn it down.

ThinkPad · #4 Post by **ThinkPad** » Thu Jan 17, 2008 8:39 pm

So would changing to a new inverter help the brightness, or is this just a symptom in the LCD alone.

jimmy274 · #5 Post by **jimmy274** » Thu Jan 17, 2008 9:30 pm

It's usually the backlight - the cold cathode fluorescent light (CCFL), used to provide backlight, wears off in time. The cathode literally falls apart in time, as it emits electrons all the time it's on. After couple of years (the usual amount is 5-6, someone correct me if they know better), the neon light is so worn out that it can't emit electrons anymore and that's when it dies. In fact, they don't die out completely, but to some point where inverter cannot deliver the amount of current the CCFL needs (the amount of current rises as the CCFL wears out), but inverter has it's own protection that shuts it off, otherwise the inverter would burn out.
Besides dimming, the usual symptoms are LCD being reddish or pinkish or yellowish (my T23 had all of these before I changed the CCFL). Inverter troubles include - no backlight whatsoever, high pitch noise coming from the bottom of the screen etc.
Bear in mind that T42 has an older technology based LCD, the T60 has newer one. I'm not sure, but maybe the T60 hasn't got the CCFL at all - but LED backlight (this is somewhat common for new laptops) - this doesn't wear off.
Another thing - the amount of time that the LCD is on, along with the number of times you've shifted it's state (on/off) has an enormous effect on the lifespan of the CCFL...

ajkula66 · #6 Post by **ajkula66** » Thu Jan 17, 2008 10:15 pm

T60 does have a backlight, however, that's an entirely different LCD, according to specs.

jimmy274 · #7 Post by **jimmy274** » Fri Jan 18, 2008 8:57 pm

ajkula66 wrote:T60 does have a backlight, however, that's an entirely different LCD, according to specs.

Of course it does George, I was merely trying to explain that some of the new LCD's use LED backlight instead of Cold Cathode Fluorescent Light - I'm just not sure that T60 has this new technology...

Padhead · #8 Post by **Padhead** » Fri Jan 18, 2008 9:05 pm

There's a guy on this board that does new bulbs for thinkpad screens. Jamiphar is his screen name. http://forum.thinkpads.com/privmsg.php? ... st&u=14512

http://www.famteam.com

He has a great reputation.

ThinkPad · #9 Post by **ThinkPad** » Fri Jan 18, 2008 10:45 pm

Thanks for the great information.

Is it possible to get the new LED technology in my T42 14 inch SXGA...

ajkula66 · #10 Post by **ajkula66** » Fri Jan 18, 2008 11:22 pm

No, it's not possible. You're stuck with what you have. And we have yet to see Lenovo implement any of that "new" stuff.

However, after James (jamiphar) had replaced the backlight on one of my A31p babies, I couldn't recognize it, the brightness was unbelievable. I highly recommend his work.

If you want, I'll send you some comparison pictures showing an A31p with a factory backlight as compared to the replaced one...seeing is believing.

jimmy274 · #11 Post by **jimmy274** » Sat Jan 19, 2008 7:50 am

I agrre with George - when I replaced CCFL in my T23, it was the brightest laptop I've seen. I've used it about 8 months after that, and the brightness hasn't degraded a lot (and I USED it, if you know what I mean). Send it to jamiphar (seems like he really does the job well), and get it replaced. The replacement job is a hell if you don't know what you're doing.

ThinkPad · #12 Post by **ThinkPad** » Sat Jan 19, 2008 12:06 pm

Do send me some pictures, im interested in this. I might opt to replace the backlight

LCD dim.....

LCD dim.....

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