Mid 2006 / model number A1181 / black or white case / 1.83 or 2.0 GHz Intel Core Duo processor.

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Backlight only at a certain angle, tried inverter board and cable

hey guys,

I have already posted here before. No backlight, tried inverter, what now?

Here is a short summary about my problem:

- Backlight did not work, but screen is visible with flashlight

- I got a picture on an external monitor when connecting to my Macbook

- I had no luck with changing the inverter and the inverter cable

With help of the F1 and F2 keys I observed that when using the F1 key in order to shut down the backlight, it was possible to bring back the backlight by pressing only ONE TIME the F2 key. But the backlight holds only for one second. Afterwards I tried this by moving the display to different angles and I found out that at a certain angle backlight will last for a very long time. This procedure only works with the F1 and F2 combination!

What could be the reason for my problem? Have I bought a faulty inverter cable?

Answered! View the answer I have this problem too

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The first place to start is by figuring out if you purchased a faulty inverter cable as you mention changing screen angles can play a part in if or how ling it works. If you own or have access to a multimeter/multitester (An analog one with the needle, is best for testing internal breaks in wires. The digital ones have slow reaction time.) you can test the integrity of the inverter cable with a continuity test (resistance test on it's lowest setting) while moving the wires around. If the needle sweeps hard at any point the cable more than likely will be the cause. By doing this you can determine if this part is at least part of the problem or not. Many people would frown upon this suggestion but, you can purchase a meter such as this and return it to the store after your minute with it is done.

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thanks for your fast help!

I would like to know if the inverter cable is OK, what else could cause me this problem? Could it be a problem of the logic board?

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The vast majority of the circuitry for the back light is on the logic board, all but the inverter and CCFL tube. Does the screen ever have a red, pinkish or orangeish hue, even slightly? When the backlight is on does it flicker? Can you hear a humming noise by the bottom of the LCD? How would you rate your experience with a multimeter? What country are you in? Thank you for including a link to your previous post here that was helpful.

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1. The screen had only sometimes a tint of blue( NO red, pinkish or orangeish hue) , but it went away when I clicked on settings -> monitor.

2. If I don't have the right angle for a working backlight, the backlight will flicker and go within a second ( by using the F1 and F2 procedure).

3. I am hearing a humming noise by the bottom of the LCD!

4. I have never used a multimeter before, but I would be ambitious enough to learn it, otherwise there may be persons who can do that for me.

5. I am from Germany.

6. THANK YOU ABCellars :)

by

It is good to hear that you have friends with experience. Please do or have a friend do the test on the inverter cable as I described. If it test good then 95%+ your problem is the CCFL (backlight) bulb. I have no source for them in Germany. I can get them in the US for less than $10USD including delivery, with warranty. The replacement of the CCFL bulb requires opening up the actual LCD and is considered a difficult procedure. I have accomplished the task a number of times and if you are careful and methodical in your in your approach it is something that can be accomplished - Depending on your CCFL source some soldering may be required. I would be willing to guide you some, also show you some tutorials on the procedure. The alternative solution will be to replace the LCD. I have purchased a number of LCDs for this laptop at very reasonable prices and with the time involved in replacing the CCFL bulb LCD replacement may be the best economical decision. I leave your financial decisions up to you.

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sorry for my late answer.

things have changed a little bit. now the backlight will only work while holding the screen with my right hand, somehow it's not possible anymore to have backlight without holding the screen. I have the impression that the screen needs some pressure in order to work. according to my last post I could have been a little bit imprecise. I can only hear the humming noise by the bottom of the LCD, when the backlight is working. otherwise there is no humming noise.

I will post here again, when I've checked the inverter cable.

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