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The March 2015 update of Apple's 13" MacBook Pro Retina Display, model A1502, features fifth-generation Intel Core i5 and i7 processors and introduces the Force Touch trackpad.

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No power, no magsafe lights. Resistor 470 looks blown.

Thanks for reading this post. I'm working with a 2015 rMBP 13" that has no power to the logic board and no magsafe light. I've already confirmed the DC-in board is good as it tested fine on another unit. LB has already been ultrasoniced.

It seems resistor "470" was blown as well as "100" above it. I replaced both and gave it a try and 470 blew again.

Does anyone know what would cause this and where else to look and what else to try? Appreciate all the help and I've learned a great deal from this site already.

Update (11/25/2017)

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Here's an image I found, it doesnt show them blown but you can see about the two I'm talking about.

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Just a quick update/answer on this. I ended up sending this to a "more knowledgable" repair company and they sent it back as a no fix saying the CPU was shorted. Not sure how that made any sense so I decided to try to tackle it myself.

Measured voltage after R7020 after I replaced the 3 caps on the PPDCIN_G3 rail and it was jumping quite a bit (anywhere from 16-19v). No magsafe light. After testing the magsafe voltage to make sure it wasn't an adapter issue I decided to replace ISL U7100 (the charging IC). That did the trick and it seems to be fully functional.

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Guys you really good and you do your research so well , you make us enjoy electronics @Reece @Bkoosy @reecee @ all technicians # one family

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@bkoosy this is not to diagnose your logic board but to identify the components you inquired about. The part with the marking 470 is reference designator R7020. It is a 47ohm 1% 1/3Watt resistor in a 805 package. The component with the "100"marking is reference designator R7005. That is a 10ohm 5% 1/8Watt resistor in a 805 package. Both components are part of your DC-in and battery connector circuitry. R7020 is part of the PPDCIN_G3 rail so you would have to test the components along that rail to see why and where it shortens out. You will need to obtain the schematic and boardview for the 820-3536 logic board in order to check those rails.

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Thanks a lot for the info on those. I guess the next step is learning how to read schematics but thought maybe someone would have a hunch of what it might be if it’s a common problem.

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@bkoosy to many components and nothing obvious will require you to check what causes this. Board level repair will require you to learn schematics and to have access to them. If it would be easy then anybody would do it and Apple could not poke us in the eye anymore ;-). Of course experts like @reecee or @tcrs_circuit may provide you with some better information

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Agreed! After you pointed me in the right direction with part numbers I found a Rossman video with a similar problem. Will do my best to pinpoint it. https://youtu.be/A1l5D1annas

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As @oldturkey03 says, there will be a component on this line shorting to ground, causing the resistor to blow (or you are replacing it with the incorrect component).

Check for a short on this line, then use schematics and boardview to find the culprit with a path to ground

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Tanks for the advice @reecee

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