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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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Dead MacBook, power running only to the SMC and nothing else.

Hey.

I have a macbook pro 2015 model with the 820-4924 motherboard. It's been dead for years. After checking with a multimeter, there was no voltage running through it even when plugged in. After looking into it I saw a shorted/burnt looking DC inboard, replaced it with the correct part (820-3584-A) and it still didn't show a charge light, but this time I had the following voltage readings running through the motherboard up until the SMC chip:

16.5V on the DC inboard's 5 pin.

3.5V on the battery's 9 pin.

3.46V on components around the SMC chip (I'm guessing components related to the chip but I'm unsure).

3.46V on the highlighted component in the image of the motherboard.

Everything after the SMC chip doesn't get any power and the SMC chip and the entire motherboard looks pristine after deep visual inspection.

After inspecting the laptop more I saw a bit more burnt/shorted discolouring on the I/O board of which i have included photos as well.

It might be worth to note the laptop previously had speaker issues (distorted sound) that weren't resolved.

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The speakers on these models were never the best, I have had 3 of them in the last 6 months and all of them needed new speakers. I doubt that the speakers are any cause of the power issues.

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Never really cared about the speaker since plugging in any sound device just fixes it and I usually use headphones. Still would love to fix this laptop if you can offer any help.

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@x4leeb post some well focused pictures of both sides of the logic board with your question. Let's see what the logic board looks like.

As an FYI, the part you've circled is L7095 and it is part of your PP3v42_G3Hot circuit. That voltage is good.

"discolouring on the I/O board" you did say you you already replaced it, correct?

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@oldturkey03 will do when i get the chance. And no, the IO board wasn't replaced. I replaced the DC inboard as it had what seemed like short damage which makes me believe my short is happening on PP3V42_G3H (?) however considering what you said that might not be the case.

Edit: for now i just want to get the motherboard functional, then I'll deal with replacing the IO board.

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I have the schematics and boardview. I checked specifically the "DC-In & Battery Connectors" page and checked the capacitors with the multimeter by seeing which one had a set ohm value (because I don't have capacitance) all of them had increasing values and eventually jumped to open loop value except C7000 where it stayed at around the same value.

Edit: I checked Pbus supply & Battery charger and noticed that the capacitors listed there all have an ohm value of 0 or close to 0.

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It does sound like you have a short in the logic board. Likely a blown capacitor, carefully inspect for blistered or burnt components or other signs of damage. You may want to get a set of schematics and board view drawings so you can trace out the power rails as that often helps me narrow down what needs to be checked first.

Given the age of the system you will need a new battery for sure MacBook Pro 13" Retina (Early 2015) Battery so you will have that expense. So keep that in the your repair budget costs.

Replace a 6600 mAh battery compatible with MacBook Pro 13" Retina (Early 2015). 74.9 Watt Hours (Wh), 11.42 Volts (V). Image

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MacBook Pro 13" Retina (Early 2015) Battery

$79.99

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I'll try doing that tho I have very little experience doing this and nothing as complicated. What software should I use to view the schematics and board view (preferably free)? And how do I find the capacitors from the schematics and board view? Any information you can give me about this would be great. Thanks.

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@x4leeb - Maybe this is a bit much for you, do you have a Mac repair shop near you? There is no shame asking for local help.


I would hate it if you made more of a mess, if you want to dive deeper I would get some junkers to play around with desoldering and soldering stuff as this does require a bit of finesse and skill. Reading and understanding schematics does require a bit of knowledge on reading the symbol hieroglyphics! Identification of the parts can be achieved view the board view drawings.


There are free viewers for the board views, the schematics are PDFs. But you still need to have the needed gear and basic understanding of microelectronics.

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While I might not have soldering knowledge I do have some electrical knowledge, I want to find the faulty part and then I'll send it off to be repaired. Thanks!

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@x4leeb - get some 90% isopropyl alcohol carefully spill a bit on the logic board just enough to wet the logic board around the capacitors and power chips note the speed of evaporation when you apply power. If you are lucky you could be able to identify what needs replacing.

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After checking the schematics and boardview I checked specifically the "DC-In & Battery Connectors" page and checked the capacitors with the multimeter by seeing which one had a set ohm value (because I don't have capacitance) all of them had increasing values and eventually jumped to open loop value except C7000 where it stayed at around the same value.

Edit: I checked Pbus supply & Battery charger and noticed that the capacitors listed there all have an ohm value of 0 or close to 0.

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X4leeb will be eternally grateful.
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