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I purchased a used iBook G4 and it seems like the power comes on fine but nothing is on the screen its just black and sometimes when turning it on it makes a static sound for some reason. Any ideas?
any help would be great thanks.
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OK it's simple but we will repeat it another time: for those who have problem with their LCD display the FIRST step is to connect the computer to an external monitor. Don't buy any part until you can do an accurate diagnostic.
(Most of the times) if you get a normal video signal on the external monitor then your logic board is probably OK.
You have a normal video feed on the external monitor but the internal display is only lightened (grey) or image is distorted then the problem is probably the video LVDS cable (bad connection or faulty) or the LCD panel has a problem. Pixels lines in the display = bad LCD panel.
You have normal video on the external monitor and the internal screen is black but you can see a faint image of the desktop when lightning the rear of the display with a flashlight then the problem could be the inverter cable (faulty or bad connection), the inverter board, the backlight.
Normal video on external monitor but video on internal display is intermittent when moving the display up and down. The display will only work at a certain angle. Most of the time the problem is the reed switch cable, a cable (double wires) that is part of the inverter cable on iBooks G3/G4.
You have no video or distorted video on the external/internal monitors and the computer freeze when booting or when moved then the graphic processor unit (GPU) is probably faulty that means replacing the logic board.
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Thanks for the great breakdown of this issue! This is the most comprehensive overview of LCD troubleshooting I've seen yet.
Thanks for the "Nice Answer badge" guys. Didn't have that one. (-:
How do you connect to external monitor?
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Hi! Does it make the Apple power-on chime sound? If you take a flashlight and shine it through the Apple symbol on the back of the screen case, do you see an Apple on the screen? If you do see an Apple, the screen could be bad, or the inverter cable could be bad. If you don't see an Apple, the screen could be bad, or it may be other factors. A good test is to connect the laptop to an external monitor. If the laptop works fine on the external monitor, then you know something's up with the screen or the screen cabling. If you don't get an image on the external monitor, then you know that the laptop's video chip has a problem, or otherwise there is something wrong with the motherboard.
Before doing any surgery on the screen, I would remove any extended RAM, the battery, and the Airport, and then reset the PMU and PRAM to see if that can jumpstart the laptop.
Good luck, and post what you find out!
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Sounds like a bad logic board- you'll probably have to replace that.
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I think it's way too early to assume it's the board. Although it could be the board, it could also very easily be a dead screen, inverter cable, etc. Even having bad memory installed could cause the computer to misbehave and not start up.
The static is what makes me think the board- I doubt the display/inverter cable as that doesn't seem likely, given the fact that the computer doesn't even get to the display.
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is there any way to test the display inverter before buying a new one?
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I wouldn't assume it's the inverter...when the screen is out, it's far more often the inverter cable or the screen itself. Like I mentioned, testing connecting to an external screen will either verify or eliminate the screen/inverter/cabling as the problem. Once you narrow it down to definitely those screen-related components, you can try replacing the parts, or the whole screen with hinge and cables. Have you tried the testing I suggested above?
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ok i hooked the screen up to a broken gateway laptop and the screen lighted up fine with no visible cracks but when i hook it back up to my apple its just black could this be the display inverter i have power coming from the logic board to a multimeter but when i hook up the multimeter to the inverter theres barely any power at all goin through it should it be like that? Thanks for all the tips i do appreciate it.
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Sounds like you're making progress! I don't have experience with multimeters so I can't comment on that. Now that the screen is confirmed, it could be the inverter, inverter cable, the video cable, or the video chip. Did you try the flashlight test I mentioned? If there is an image but it's just dark, that narrows it to the inverter or inverter cable. If there is not even a dark image, it could be the video cable or the video chip...
...the inverter and inverter cable are responsible for the backlight, and the video cable and video chip/board are responsible for the image. Based on what you see or don't see with the flashlight test, I would start replacing parts accordingly in order to further rule them out. If you do see the Apple and it's just dark, in my experience it's the inverter cable...I've very rarely seen a bad inverter, but who knows.
Another note, outputting the laptop's video to an external monitor is probably the easiest way to rule out the board being bad, i.e. if external video works, you have a good board and know the problem is in the screen parts, which you can then replace. I would definitely try this before replacing screen parts...it would be a shame to spend time & money on screen components only to discover the board is bad.
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ok i will try that and keep you posted thanks for the help
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This is not an answer. Please delete this answer and edit your question to add more information.
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ok my screen backlight definately works because when i hooked it up to my old gateway it lit up fine but there was still no images on the screen i dont know if this is because it was hooked to a gateway that was stuck in sleep mode or not i figured it would at least maybe show something when i turned it on but it just lighted up from the backlight and the sreen remained black dont know if this hepls at all. i am still workin on the test you reccomended @rdklincorporated
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ok so exactly how do i try and hook it to an external monitor i really never tried this but i will tonight if i here back from you. THANKS
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It requires a dongle like one of these:
[linked product missing or disabled: IF153-032]
There are also ones with DVI, VGA, etc. Hopefully one came with your machine?
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not really sure how to update the question im new to this site. I just hooked my screen back up to my ibook g4 12in. and the backlight came on for a second with with like 2inch lines goin vertical on the right side of the screen and then they went away. Does anyone know what would cause this because when i had the screen hooked up to my old gateway the backlight stayed on but there were no lines or images. thanks
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Mike, please update your question with new information rather than posting new answers.
look, this guy is obviously confused about the system here, and rightly so,it is rather confusing, give him a break there, no need for the harsh -votes
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2 Comments
i just tested the wires running to the screen with a voltage meter and the voltage was very low does anyone know what it should be around. just curious
by mike
i keep turning on but still black with apple picture on my screen
by godbil2003