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Nick Stewart
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Black screen on boot but chime sounds

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I have just been given a Macbook 2009 that wont turn on. When you press the power key you hear the normal boot chime but no picture appears.

The laptop was given to me without any hard drive, so I installed a blank 250GB HDD. The HDD has no OS on it, and I am not sure how it is currently formatted as it is new.

Even when I use an external screen and regardless of whether a HDD is present the macbook does not show any sign of life on the screen or external screen but still chimes.

Any help would be great,

Nick

Edited by: oldturkey03 ( )

I have now found that the GPU is not the problem. External display is fine, and shining a torch at the screen the picture appears fine. The problem is there is no LED backlight on the screen?

Nick Stewart,

For best results follow lemerise's good advice. + for both.

rj713,

I agree with lemerise and rj713. Also the 90% or better ISP for cleaning the board/connectors, as suggested by lemerise, is just fine and it's manufacturing is better regulated than denatured alcohol, as it is a pharmaceutical - controlled by the FDA. Denatured alcohol is not regulated, nor are the facilities making it inspected.

ABCellars,

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lemerise
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From your question update I understand that the macbook GPU is good and you get video on internal and external screens but no lightning on the internal. This is often a problem caused by liquid spilled on this macbook model. You should carefully clean the LVDS socket that brings video and lightning to the LCD screen. Check for socket internal discoloration like black spots or corrosion. Clean it with a tooth brush and 90% isopropyl alcohol. Check also the LVDS cable connector which may need to be cleaned too.

Edited by: lemerise ( )

Thank you, can I use contact cleaner instead? Do you know where the fuse is on this model? I have pictures of the logic board I could post from this MacBook.

Nick Stewart,

90% percent alcohol won't do the job. You need to purchase 99% from a drug store ,call around. I personally use denatured alcohol on all logic board cleaning but you still have'nt answered the question of if you can see the image faintly with a flashlight. You might not need the cleaning at all that would just need a new screen or led backlight inverter.

John,

Yes I can see image clearly, I replaced screen last week along with LVDS cable. I beleive it to be the connector or the fuse as has been said, just have not got the expertise to fix it :(

Nick Stewart,

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John
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Are you using the external monitor correctly in clam shell mode?

Try this first , put the installation dvd. Power it on without pressing anything any key commands , immediatly close the lid when it fires up and plug in the external monitor wait with the lid closed unitl the installation dvd comes up. If all goes good you will be able to use your mac and at least know it works , but this will tell you if you your screen or video cable or backlight or backlight fuse is bad. Then on to the next!

Edited by: John ( )

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JoshuaK
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You could also shine a light into the middle of the screen and look for the blinking folder icon, that would indicate the backlight is not working. If it is an MC207 model, it is a LED-backlit screen and will need to replace the whole screen.

Update

As I understand it that is a problem with the GPU and reballing the solder underneath will fix it. There are plenty of repair places you can send it to for 100-125ish to fix it. This is not something that would be able to be done at home with normal tools. I have also seen a temporary fix of using a heat gun to attempt to resolder broken points, but its only a temporary fix when it does work, and most of the time it does not.

Edited by: JoshuaK ( )

have you shined the flashlight like they said to do you will see faint image . if your getting nothing your backlight fuse or WLED driver chip has blown.

John,

Totally wrong John, if their is a faint image then the problem is with the backlight, as there is an image, only one not bright. If there is no image, then the problem is not in the backlight system or there are multiple problems. - With a bad WLED driver or burnt fuse to the booster circuitry for the backlight, there will be a faint image on the screen or there is nothing for it to enhance/make brighter.

ABCellars,

ah your kinding of confusing that's what i said to begin with @ABCellars

John,

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John
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I would bet money you have a in-line p link fuse or the WLED driver which is a QFN chip blown. Your going to need to need some real expertise to test the QFN chip with very fine probe tips to test it and there is a possibility of shorting the board cause the contacts are so close. Me personally? I would change them both but soldering a QFN is extremely hard youtube QFN and you can see what i'm talking about.

Edited by: John ( )

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