T42 Screen turns pink then out

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gokyori
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T42 Screen turns pink then out

#1 Post by gokyori » Fri May 01, 2009 8:40 am

...So it seems like a common problem, my 15" T42 UXGA screen goes from pink to working to black. An external screen works perfectly. From reading, my understanding is that it is either the inverter or the CCFL or both. Furthermore, the pink indicates CCFL and the black could be either. I would have no problem tackling either replacement. My question is in the parts. I've taken the lid off but not apart, the tag on the end of the cable has the following two bar code numbers; ASMP92P6721 and the longer one LCD11S92P6672Z1Z8PJ837102 40B-do I need to look at the actual LCD screen to make sure it matches the FPU 92P6683 that IBM lists as the 15" UXGA to match with a new inverter? Secondly, Will any CCFL 2mm x 305mm work as a replacement?
Thanks

richk
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Re: T42 Screen turns pink then out

#2 Post by richk » Fri May 01, 2009 10:33 am

Pink color is always the bulb. All the 305mm bulbs will work. One warning: I have done several screens and I have never really had much luck getting a satisfactory repair. If you are careful and have the propper tools, you can get a working screen, but all the replacement bulbs seem to be just a very small amount too short or they don't light all the way to the end. There is always a shadow in each corner. Also, the work is supposed to be done in a clean room. I always end up with some spots (dust?) inside.

Binh
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Re: T42 Screen turns pink then out

#3 Post by Binh » Fri May 01, 2009 6:11 pm

gokyori wrote:my 15" T42 UXGA screen goes from pink to working to black
Gokyori, the pink is observed a long time before ? My T42p UXGA screen is showing pinkish tint for 30s from startup and I am curious how long it will serve before replacing the backlight.

And how about your screen's brightness now ? Mine is still bright enough.
Compaq 386SX > AST 486SX-25 > TP 390E > Compaq N410C > T41 2373-9U5 > T42p 2378-RVU UXGA 1.7@2.45GHz > T60p UXGA modded to T61 8889-ACG with T8300 OCed to 3.2Ghz@1.20V, undervolted to 1.6Ghz@0.775v, Nvidia NVS-140M undervolted to 0.9v, PCI-E ASPM enabled, 11W power in idle.

gokyori
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Re: T42 Screen turns pink then out

#4 Post by gokyori » Fri May 01, 2009 6:36 pm

Binh, The screen started turning pink, maybe 2 months prior. It always brightened after a minute or two, then one day after running for maybe an hour, it went black. It rapidly grow worse until it would turn black almost immediately. The tech at Lenovo diagnosed the problem as a bad inverter or in need of a new LCD panel, but was little help beyond that because the warranty had expired. After many hours research I ended up here. I don't know if they all follow the same path to the dark side.

Binh
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Re: T42 Screen turns pink then out

#5 Post by Binh » Sun May 03, 2009 1:27 am

gokyori wrote:Binh, The screen started turning pink, maybe 2 months prior.

The tech at Lenovo diagnosed the problem as a bad inverter or in need of a new LCD panel
Thank you for information. 2 months is two short from the first symptom to the moment it downs completely.
AFAIK, the tech at Lenovo is wrong talking about inverter. I have the same opinion as Richk that the problem is in backlight bulb. You can change the backlight by using the service of a member with nick Jamiphar.
Compaq 386SX > AST 486SX-25 > TP 390E > Compaq N410C > T41 2373-9U5 > T42p 2378-RVU UXGA 1.7@2.45GHz > T60p UXGA modded to T61 8889-ACG with T8300 OCed to 3.2Ghz@1.20V, undervolted to 1.6Ghz@0.775v, Nvidia NVS-140M undervolted to 0.9v, PCI-E ASPM enabled, 11W power in idle.

beeblebrox
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Re: T42 Screen turns pink then out

#6 Post by beeblebrox » Fri May 15, 2009 1:31 pm

Pinkish: 100% Backlight failure!

Means, mercury is depleted in either the phosporous layers (happens after a few years) or a crack in the tube at the connectors.

Just get another 15" LCD maybe with a cracked screen and take the CCFL from there. They all have the same standard diameter.

Binh
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Re: T42 Screen turns pink then out

#7 Post by Binh » Fri May 15, 2009 6:31 pm

beeblebrox wrote:Pinkish:
Just get another 15" LCD maybe with a cracked screen and take the CCFL from there. They all have the same standard diameter.
Can you say exactly what diameter it is ? I have heard that ID Tech 15" flexview LCDs use 2.6mm backlight CCFL, but some other sources say that they use 2.0mm CCFL.
Also, can I use CCFL from a cracked DESKTOP 15" LCD ?
Compaq 386SX > AST 486SX-25 > TP 390E > Compaq N410C > T41 2373-9U5 > T42p 2378-RVU UXGA 1.7@2.45GHz > T60p UXGA modded to T61 8889-ACG with T8300 OCed to 3.2Ghz@1.20V, undervolted to 1.6Ghz@0.775v, Nvidia NVS-140M undervolted to 0.9v, PCI-E ASPM enabled, 11W power in idle.

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