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2 2015 MacBook Pro Thermal Throttling (Kernel_Task) After New Battery
Seeking the assistance of all the iFixiters out there to solve a mystery I’m having with my MacBook Pro.
So to preface, I have run a iPhone, iPad, & Mac repair business for 10 years now and have extensive experience with Apple devices, however this one is stumping me.
So, a few months back a friend of mine hired me to fix his MacBook Pro. He stated that it was running slow so he decided to do an OS update and half way it failed and now won’t turn on.
Initial diagnosis was that I could not get the machine to boot. I then noticed that the trackpad would not click down. In hindsight I recognize this is because this model has a Force Touch trackpad that only clicks when the computer is on.
However I assumed that this could be an indicator that the battery was swollen. I removed the back plate and sure enough the battery was swollen.
I told my friend that the computer needed a new battery desperately and this could very likely be what caused the computer to die during the update. This being said, I ordered him a new battery from iFixit to be installed.
Jump 2 weeks later when I have the battery in hand, he drops of the MacBook Pro to have me complete the replacement. Unfortunately, in the time waiting for the battery to arrive the battery has bloated even MORE.
Given that this model has the battery glued in, & that the battery is bloated to this extent, I told the customer that unfortunately I could not move forward with the repair due to the risky nature of LiPo batteries when bloated.
He decided that he wanted to give it a go on his own so he bought the battery off of me and borrowed my tools. He was able to successfully replace the battery with no fires 😮💨 .
This is where it gets weird. Post battery install the computer turns on, however the only key on the keyboard that works in the power key and the trackpad is non functional. The fans also ran full blast and the computer ran really slow (I was able to test the computer with external mouse and keyboard but as mentioned VERY SLOW).
At this point, I took the laptop and fully disassembled it again to check all cables and insure all was connect correctly. It was.
It should be mentioned that many years in the past this computer came into contact with a small soda spill on the keyboard. Apparently the spill never caused any issues. I also didn’t see any corrosion or signs of liquid damage at all inside the machine, which I took as a good sign.
I did some extensive research and found a great many iFixit articles about this issue and the consensus was that the fix was a new trackpad cable.
I assumed that perhaps the trackpad cable was damaged during repair and now that the trackpad doesn’t work it can’t read the thermal sensor in the trackpad which is causing it to run at max fan and thermal throttle.
At this point however my friend was eager to get a laptop up and running, and frustrated with the time and money spent on the 2015 MBP, so he decided to pull the trigger and upgrade to a new MacBook Air.
For all my time guiding him through the process and answering questions he paid me with the semi functional 2015 MBP to tinker with at my expense.
I decided to order a new trackpad cable, trackpad, and uppercase with keyboard.
I installed all of these and Voila, it booted up, keyboard works, trackpad works, no fan noise! So, I called it a success. Only when I started using it did I realize truly how slow it was, beach balling, could barely run 2 apps at once, activity monitor says 12ish percent idle. This is with fresh install of Big Sur.
When I checked my activity monitor I noticed that system was using 70+ percent of the overall cpu and that kernal_task was using 500+ percent of the cpu at idle. However still no fans.
I did extensive research about kernel_task and did all the recommendations as follows:
SMC reset, PRAM reset, fresh install of OS, Apple diagnostics (no codes except “could test power adapter” since my power adapter was connected at the time of diagnostics), I followed some instructions to attempt to delete .kext files from my library/extensions to fix kernel task but the files mentioned in the tutorial don’t exist on my machine??
Then I started having this issue where the computer would not boot at all unless I held down the power key for at least 5 seconds. Apparently, this preforms an SMC bypass. So I can’t boot if I don’t do an SMC BYPASS or I can do an SMC reset each time I boot then I don’t have to hold the power key.
Either way to boot I have to preform either the SMC BYPASS OR RESET THE SMC. If I remember correctly this booting up issue started after the first SMC reset I performed.
I even went so far as to do PRAM & SMC resets with the battery disconnected too. No dice, however I found out something interesting, when booting on AC power with no battery connected I have no issue booting, no need for SMC bypass or reset.
So the battery is implicated in this somehow. Then I read online that Mac’s sometimes get weirded out by non OEM batteries and cause issues like this. Even cause kernel_task.
I read also that you could update your SMC firmware and that helped out a guy online with this issue post battery install, but I can only find an update file for mid 2012 retina MBPs not 2015 models. So I don’t think it will help me, maybe I’m wrong.
See update link for 2012:
https://support.apple.com/kb/dl1559?loca...
So I am totally stumped.
I really want to get this thing up and running & any help would be greatly appreciated.
Saludos from Mexico 🇲🇽,
-Milo-
Update (08/27/23)
@danj Removed heat sink and now understand Fb what you mean by the black shield. Removed the shield and there is a large amount of paste covering the chips, both old and new paste.
Guessing this is what I should remove…?
Update (10/14/23)
UPDATE: I had the opportunity yesterday to have a friend who works at an Apple Store to run Apple Diagnostics on my MacBook Pro. It showed many errors regarding sensors and power/voltage readings on the logic board. He recommended an SMC reset, but I explained I had already tried that.
The concluded that there is a chance that the issues are caused by the non OEM iFixit brand battery. This is something I also read online regarding it being caused by a non OEM battery.
These issues started after I replaced the battery, which would back up that hypothesis.
I attached the images of the Apple Diagnosis thinking they might be is interest to you.
Interesting side note. I also own a mid-2013 13inch MacBook Air. Several years ago I replaced the original battery with an iFixit one and it has been working perfectly ever since.
THEN, about a week ago, to disprove the idea that it was a failed ssd causing issues in my 15 inch MacBook Pro, I swapped the SSDs (MacBook Air SSD into MacBook Pro and vice versa) since I knew the MacBook Air ssd was good and they are cross compatible.
It made no difference for the MacBook Pro, it still had the kernel_task issue, so I put the SSDs back to their proper positions, I forgot about it.
3 days later, my MacBook Air won’t turn on without the AC adapter connected, doesn’t recognize the iFixit battery (which had been working for years) and NOW has the same kernel_task issue as the MacBook Pro.
The ONLY two things these Macs have in common is that for an hour I swapped the SSD from the MacBook Pro into the MacBook Air and I also use the same AC adapter for both Macs.
Could the SSD from the MacBook Pro which had the kernel_task issue originally have somehow corrupted the SMC on the MacBook Air after I swapped them temporarily.
The MacBook Air has the proper SSD reinstalled and I have attempted SMC resets on the MacBook Air, however it still does not recognize the battery and has the kernel_task issue.
P.S. you will see in the diagnostic pics that there were issues flagged regarding the “power port”. Could this be related to a bad AC adapter. I have several MagSafe 2 adapters and have tried different ones on both computers to now avail.
Just wanted to give you an update since it is a very strange issue.
Saludos,
-Milo
crwdns2934109:0crwdne2934109:0
crwdns2944067:04crwdne2944067:0
Good morning,
I am no expert here, however that looks like a hell of a lot of thermal paste. As @danj said, i would start trying to remove as much of it off the capacitors as possible. This could be resulting in the capacitors overheating because they are design to run on airflow, not thermal compound.
Good luck :)
crwdns2934271:0crwdnd2934271:0 Nick P crwdne2934271:0
@mfirestar and @np_f1_2021 - Yep TIM is not something you want around the capacitors The TIM effects the capacitors inductance.
Here's a fun experiment to tryout take an aluminum tube which a steel ball can travel down. Carefully drop the ball down the tube it should travel quite quickly as it shouldn't be magnetized. Now a coil to induce magnetism into the ball (it needs to be a strong force) not sent the ball down the same tube what happened? Here the magnetic flux interfered with the aluminum tube.
While different here the same kind of effect happens as the TIM covering the caps alters their effectiveness! This is what I use loaded with 90% Isopropyl alcohol Refillable Aerosol Spray Can Sprayer and a soft tooth brush to fully clean the green carrier and the SMD devices on it.
crwdns2934271:0crwdnd2934271:0 Dan crwdne2934271:0
@np_f1_2021 @danj Thank you both for your responses. I had the opportunity to clean off much of that excess Thermal Paste. I didn’t have the opportunity to acquire isopropyl alcohol, however I am using my iFixit anti-static brush with the Articlean Thermal Compound Removal product and it is looking much better.
Interestingly, a lot of the paste was from my most recent application. I recognize I used an excessive amount of paste the most recent time I reapplied it, however much of it also looks very old and dry as if it leaked under the black shield long ago.
I am going to give it a final clean tomorrow and will reapply a much smaller amount of paste and will let you both know how it goes.
Thank you for all the info!
-M
crwdns2934271:0crwdnd2934271:0 Milo Feldt Nichols (TechsMex) crwdne2934271:0
@np_f1_2021 @danj Had the opportunity this morning to clean off the CPU/GPU chips and remove the extra TIM from the chips around them. I then reapplied Arctic Silver but a more reasonable amount (I used your tissue technique to estimate to amount) and reinstalled the heat sink.
Unfortunately, kernel_task is still chewing upward of 600% of my cpu at idle. I downloaded iStat Menus and verified the temperatures of all my sensors. Nothing above 40 Celsius.
The fans are running at an appropriate speed however I even tried forcing them to spin at max. The temps dropped but kernel_task took no mind.
In activity monitor it still says that “system” is using upwards of 70% of the CPU at idle.
Thank you for all of you help and if you have any ideas, lemme know!
-M
crwdns2934271:0crwdnd2934271:0 Milo Feldt Nichols (TechsMex) crwdne2934271:0