MacBook Pro 15" Unibody Late 2008 and...

Released October 2008 / 2.4, 2.53, 2.66, 2.8 or 2.93 GHz Core 2 Duo Processor

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How to repair a 15" MacBook Pro motherboard?

Blown Capacitor

Zoomed out for reference.

I bought this computer on ebay because they said it had been dropped and the screen broken so I figured that it would be a simple display swap to get it working again. The computer model is a 15" Macbook Pro Core 2 Duo 2.8Ghz Unibody mid 2009.

However that did not work and upon further investigation it looks like a capacitor on the motherboard has blown. It is right by the optical drive you can see the location of it in my zoomed out picture. It looks like its just one cap and its very obvious it even left a little smoke trail that I've circled.

So my question is does anyone know what value that cap is or how to find out without having to buy a broken board on ebay for 150 just for a 10 cent part.

I welcome any thoughts about if that would even fix it. Currently the display is the only thing that doesn't work. When hooked up to an external display it works like a champ.

Answered! View the answer I have this problem too

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What are the last three of your serial number? this will help to properly identify your board.

by oldturkey03

that'll be 23 cents....;-)

by oldturkey03

I did buy the part and finally had time to put it on and it did fix the wifi!!! So now that is working. Yay! :) Now I've figured out that the display is actually working but the backlight is just messed up. So now to figure out what I need to do to get that working again and I'll be in business :) I've been trying to sort out truth from fiction over on this http://forums.macrumors.com/showthread.p... forum but its tricky and I'm not sure what all the differences between those 13" macbook pro's and my 15" macbook pro are. I just wanted to provide an update in case anyone needs that answer too. If anyone has any thoughts on how to trouble shoot the backlight circuitry I'd be glad to hear them. Thanks again oldturkey03 for your help getting my wifi working again.

by ivanmacuser

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ivanmacuser, I used the 820-2523-B from your image to locate the part. It is not a capacitor. The component that got "smoked" on your board, is logic board designator L3404, it is a FERR-120-OHM-1.5A. It is a ferrite bead used for EMI control. If it "smoked", and it sure looks like it did, then you definitely had significant current passing through it. Before you replace it, check to make sure that you do not have a short somewhere else. Check the resistance to ground which should measure 0ohms. Something like this http://www.digikey.com/product-detail/en... should work for you. Not sure where you are located, so the Murata number is BLM15EG121SN1D. The interesting part on this is, that this component is actually part of the WLAN circuit. So you may have some other issues as well. However, replace this one and re-evaluate. Hope this helps, good luck.

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Wow ok that was extremely helpful. Sorry if I'm a little dense but how would I go about checking the resistance to ground? I have a multimeter just not sure what to check. Sorry I didn't get the serial number to you in time it looks like you got around me being away from the computer though. Does it make sense that that chip would be preventing my display from working? I'm not really sure what an EMI control does.

by ivanmacuser

As far as the WLAN goes I was told the wifi didn't work either but I had figured that was because the display was missing since that sort of makes the wifi quit working. I guess it may be a little more serious than that.

by ivanmacuser

Thank you for accepting my answer. An EMI filter really just protects surrounding electronics from interference and "noise" of course in a WLAN this is somewhat important for data protection etc. I checked the schematic and I do not see any reason why this filter would stop your display from working, but remember, anything is possible and it is close the the backlight circuitry and display connector. So take another close look at the rest of the components. For testing purposes of the circuit, you can temporarily bridge this filter and see if it makes a difference.

by oldturkey03

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ivanmacuser will be eternally grateful.

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