IBM T43 LCD Failure

[MoeHScott]

Hi. I have an IBM T43 laptop running Windows XP that appears to have a failing LCD screen. Originally, when the laptop was turned on, the backlight would initially turn on--but with a reddish tint--and then turn off only a few seconds later. A faint picture could be seen on the display upon closer inspection. I replaced the LCD's backlight with some success: the screen would now light up, but was unevenly lit. So, I took it apart and put it back together again, but this caused a perplexing result: the backlight would turn on with the initial startup, and then turn off a few seconds later, and then turn on again during the Windows XP loading screen, and then turn off again before the computer finished starting up.

This process repeated in the exact same manner each time I started up the laptop, leading me to believe that maybe the inverter board, which controls the backlight, was now at fault. I replaced the inverter board without any change. I then re-imaged the hard drive (which I was going to do anyway because the computer was running extremely slowly), thinking that a problem with a driver might be causing the LCD to fail. After re-imaging, the backlight now turns on initially, and just a second later turns off with a high-pitched hissing noise, and then repeats this one more time. The display works perfectly with an external monitor, so I suspect that this is not a software-related problem.

What should I do now? If anyone has an idea of what this problem could be, your response would be very much appreciated. Thanks!

[hunterman223]

Hi, a reddish tint means that the backlight (ccfl) is going out. It is possible to replace it, but it is a real PITA. Look for a new lcd on ebay, or post a WTB (Want to Buy) in the marketplace forum.

[RealBlackStuff]

You could have a bad solder contact on the wire on either end of the CCFL.
Resolder them if you can.
You just need to remove the silicon covers, then push the CCFL out just enough to one side to resolder.
Repeat at the other end. Then put the covers back on and reassemble.

[MoeHScott]

Thanks for the responses! Just for clarification, the display does not have a reddish tint anymore; I at least fixed that problem. I'm also not sure that it is a solder connection issue, because the backlight lights up and turns off the same way each time I start up my computer. Would it even turn on at all if the solder connection was bad?

[RealBlackStuff]

The hissing noise points to a bad connector or a soon-to-fail inverter.
Try reseating the back of the LCD cable in the LCD, reseat the LCD cable onto the monitor, and reseat the inverter onto the LCD cable.
If it still 'hisses', it's probably a bad solder connection on either end of the CCFL.
Read my post here for some info-points: http://forum.thinkpads.com/viewtopic.php?f=31&t=88991

[4ckatro]

Hi!
I have two t42 laptop. The first one drink with wine and the second one i have dropped.
So in the first one the motherboard dies, and the second one the sreen have broken.
I am newbie in repairing IBM, but i have change a lcd panel in my broken T42, but when i turn on, the screen come in, but there is no backligh.
Can somebode help me, how can i fix it?
Robert


+

I found the F7 fuse is wrong. If i short this circuit is it possible to work?