2 MacBook 12” 2015 won’t power on after battery replacement
I have a 2015 12" Retina MacBook that I performed a battery replacement on, following the iFixit guide. However, after reassembling the MacBook and following the instructions for applying low voltage, the MacBook will not turn on.
When I first performed the battery replacement, I did not read the guide well enough and plugged it straight in to 12V power. I thought this had killed the logic board, as it would not turn on. So I purchased a donor machine (exact same model), which I confirmed worked before disassembly, and attempted a logic board swap. After swapping the logic boards between the two chassis and then back to their originals, neither one will power on. I have tried the 5V power trick to no avail.
I'm really stuck on this problem, as I now have two identical MacBooks with known working batteries that will not power on. I have tried different 5V power adapters, different USB-A to USB-C cables, and every combination of logic board and chassis. I have also repeatedly re-seated the USB-C port connector on each logic board, ensuring they are snapped into place correctly. I'm fairly certain all the rest of the flex cables are plugged in correctly, including the keyboard/trackpad cable.
When plugged in with a USB-C voltage reader, the readings are:
- 5.0-5.1V (as required after battery installation, depends on adapter used)
- 0.0475-0.07A (hovers depending on adapter and cable used, also varies slightly between the two machines)
- Average of 0.3W
With the wattage reading in particular, I've noticed strange behavior. I have attempted resetting both the PRAM and SMC, and only resetting the SMC seems to make a difference. When the SMC is reset, the wattage reading goes down to about 0.1W and then quickly returns to 0.25-0.3W. When the power buttons are pressed, the wattage spikes slightly as high as 0.4W. And, weirdest of all, there was one case where resetting the SMC and pressing the power button spiked the wattage reading to over 1W, but only for a second.
Anyone experienced issues like this? I've tried every troubleshooting step I've come across on iFixit and Reddit, etc., so new ideas would be appreciated. Thanks!
Guida
Connettere a bassa tensione dopo ogni riparazione (solo MacBook Retina 2015)
Difficoltà:
Molto facile
—
1 - 15 minutes
Guida
Sostituzione batteria Macbook Retina 2015
Difficoltà:
Difficile
—
2 - 3 hours
Questa è una buona domanda?
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=Two quick questions that might help me answer your question: did you purchase the battery replacement from iFixit? Also, did you use an ESD grounding device and insulated tools when conducting the repairs?
da teardown-er
No to both. At first I thought it was the off-brand battery at fault, which could still be true, but the replacement battery does power the board as indicated by the fact that the power light comes on with both logic boards. And as far as tools go, I’m using all iFixit tools.
da Owen Sullivan
Ok, then it sounds like the battery works fine (or good enough to test the logic board at least). iFixit tools are good, and if you were using them its very unliky that you shorted something out even if you didn't use an ESD strap. That being said, it's generally a good idea to wear a grounding strap when working on logic boards
da teardown-er
@sulliops sounds like your board(s) are not communicating with the charger to request higher voltage. Since the replacement first worked but then quit after you installed it in your original chassis, I wonder if something shortens out your boards. Have you tried your old, or a different battery, just to rule the new battery out as a potential cause?
Commonly, if the ammeter shows 5V with very low amperage (<0.1A) (that would be ~0.5W, but stick with Amps since that makes it more specific and easier), there is a short circuit, usually on PPBUS_G3H, PP5V_S0 or a faulty CD3215 chip.
da oldturkey03
@sulliops Is the board thin enough to repair? Yes, but just like anything else, you want to practice replacing components on a logic board if you have never done it :-) Where can I find replacement MOSFETs? You want to establish that it is a MOSFET that has failed. Common error will be failed capacitors. The charging IC CD3215 is a TQFN package and would require a hot air rework station to be replaced. Replacement of all those components are readily available at many online electronic parts suppliers. Anyhow, post some really well focused images of your board(s) with your question (both sides) that way we can see what you see and hopefully guide you through the trouble shooting. Aggiungere immagini ad una domanda
da oldturkey03