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苹果2016年对于专业用户的笔记本更新。具有15英寸,2880*1800的Retina显示器, 四核心 Intel Core i7处理器, 256 / 512 GB /1 TB / 2TB 存储空间, 16 GB 内存, 和一个带有Touch Bar的键盘。2016年11月发布,型号为 A1707。

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To all the GBA Reballrepair neuro surgeons... expert question

My Macbook 1707 PMIC got hot. Removed the chip and the fifth pad from the bottom left (PP5V_S4) was carbonized (also the exact trace to this pad is not obvious). After carefully scraping the pad to expose some copper it shows a 0.3 ohm short.

I know this is a complex issue but what is the best way to deal with this?

Assuming ground is the top layer surrounding each pad, is the right way to deal with this to scrape away the ground top layer around this pad? If it's not the best way to deal with this, what do you recommend ?

Thanks for your guidance.

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Dealing with missing pads depends on what IC they are under and the position of the pad. It is not easy finding a trace under a buck converter as sometimes you have to scrape down a few layers to find it and you risk severing other traces on different lines if you scrape down to many layers.

In your situation I would put some UV mask on the pad and just run a jumper from the closest PP5V_S4 component, it’s a no-brainer if the pad is on the outside.

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Thanks Chris. As you can see on the picture it's on the outside (fifth pad from the bottom left) but I am afraid this very pad is shorted as I have .3 ohms on this pad.

Couple of questions:

1) Is it fair to assume that if the trace on which I'd put solder mask on is shorted, then the short will remain so I don't understand how this would work.

2) If the original V5S4 pad under the PMIC feeds V5S4 to many other places, wouldn't I'd lose all these other connections if I bypass the original trace?

Just trying to understand your proposed fix. thanks for the help.

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Dan I don't have a microscope camera yet. That's the best picture I can take with my iphone through the microscope.

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@jmd1010 - You didn't get in imbedded yet! You got it to the image toolbox but its not visible until you past the image link into your question.

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@jmd1010 Oh my, there has been a lot of heat put on this board. Are you sure your multimeter isn’t on diode mode? If it is this value would be acceptable. If not you need to test another component on that line to rule out your probe isn’t touching ground at the pad.

Once you have determined you actually have a short you need to find the shorted component. Once you have replaced the component you can run a jumper to the missing pad.

I would first clean all the reflowed solder around the area so there is nothing bridging.

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We really don’t get this deep as most people here are more focused on assembly level replacement for the repair.

You really need to get your hands on the schematics and board views for your system. Do a search for 820-00928 which is the board number, you should be able to find someone who found them after falling off the back of the truck ;-}

You should jump over to Louis Rossmann’s site Louis Rossmann - 15” MacBook Pro - 1707 repairs

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Hi Dan, I have both the schematic and boardview but they are of no use to address this problem. Hope someone with experience in component level repair could provide guidance.

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@jmd1010 - Good! You should be able to ID the signal the pad offered/needs. Even still you need to figure out what was the cause of the issue. Did you have liquid damage, another part messed up so this is a cascaded reaction.

Maybe Chris @imicrosoldering can help you but he will need a good tight picture of the damaged area as well as another zoomed out image so he has a reference of the board layout position. 在已经存在的问题里加入图片

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No water damage. It is a case of a faulty charger.

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@jmd1010 - Did you have liquid damage, another part messed up so this is a cascaded reaction.

9 hours ago by Dan

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@jmd1010 - Ah, sorry ;-{ Didn't get the linkage.

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