MacBook Slow with Loud Fans after Battery Replacement

Question

MacBook Pro 15" Retina Display Mid 2012 Repair

2.3GHz, 2.6GHz, or 2.7GHz quad-core Intel Core i7 processor (Turbo Boost up to 3.7GHz) with 6MB shared L3 cache.

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Will Gyory @willgyory

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crwdns2931729:0crwdne2931729:0: Sun 11, 2019

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MacBook Slow with Loud Fans after Battery Replacement

I just replaced the battery in my MacBook Pro using the iFixIt replacement kit. I got exactly the right battery kit: MacBook Pro, Retina Display, 15’’, Mid-2012.

Everything went smoothly when replacing the battery, but now my laptop is barely usable: everything is painfully laggy, including cursor movement/typing, and the fans run on maximum constantly.

I tried the SMC reset—no effect.

I downloaded coconutBattery to get some info, but not sure what to make of it:

Any ideas what might be the problem? Thanks.

EDIT:

I am adding this screenshot of Activity Monitor, which shows that kernel_task is running at over 700% CPU capacity, whatever that means.

EDIT 2:

Here are two screenshots of the app “TG Pro." Everything looks green except for the fans, which probably just adds to the mystery…

EDIT 3:

I ran the Mac hardware test by holding “D” on restart, then following the prompts. Here is a photo I took of the results:

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Dan @danj

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Self employed contract worker

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crwdns2931729:0crwdne2931729:0: Sun 11, 2019

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Well, your battery info looks good! The kernel_task issue is caused by a sensor issue. Lets see if we can ID it using this app TG Pro post a snapshot of the main window so we can see all of the sensors (you may need to grow the window)

The error you are seeing is: 4SNS TsOP - 124 - Palm Rest Temp sensor. You’ll need to inspect the trackpad connection on the logic board. Using a magnifier inspect the connects on the logic board and the cable you may have damaged one or two of them. If they are OK then the table its self or the trackpad are damaged.

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Thanks! Please see screenshots added in “Edit 2” above. Hope they are useful.

crwdns2934271:0Sun 11, 2019crwdnd2934271:0 Will Gyory crwdne2934271:0

Sorry guy ;-{ I was hoping TG Pro would have shaken out the sensor. Often times when the logic board is taken out something is not reseated correctly. None of the monitored sensors have failed.

There are still a few sensors that are not monitored within TG Pro but are within diagnostics. Lets give that a try. Restart your system and press and hold the D Key. Let us know if an error popped up and its code hopefully we can decode it.

Reference: Mac startup key combinations

crwdns2934271:0Sun 12, 2019crwdnd2934271:0 Dan crwdne2934271:0

Nice—that seems to have picked up on an issue. See “Edit 3” above. I took photos of the other tabs of that dialog box, btw, but they didn’t seem to have any useful info so I left them out. Let me know if I should upload those as well. Thanks for your help!

crwdns2934271:0Sun 12, 2019crwdnd2934271:0 Will Gyory crwdne2934271:0

Hmm, I did press pretty hard when I was scrubbing the adhesive off the backside of the trackpad. I think I’ll bow out at this point and let Apple do the necessary repairs. (I’m not jumping with joy at the thought of opening the laptop up again myself.) Thanks for helping ID the issue though!

crwdns2934271:0Sun 12, 2019crwdnd2934271:0 Will Gyory crwdne2934271:0

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Thanks! Please see screenshots added in “Edit 2” above. Hope they are useful. — Will Gyory
Sorry guy ;-{ I was hoping TG Pro would have shaken out the sensor. Often times when the logic board is taken out something is not reseated correctly. None of the monitored sensors have failed.

There are still a few sensors that are not monitored within TG Pro but are within diagnostics. Lets give that a try. Restart your system and press and hold the D Key. Let us know if an error popped up and its code hopefully we can decode it.

Reference: Mac startup key combinations — Dan
Nice—that seems to have picked up on an issue. See “Edit 3” above. I took photos of the other tabs of that dialog box, btw, but they didn’t seem to have any useful info so I left them out. Let me know if I should upload those as well. Thanks for your help! — Will Gyory
Hmm, I did press pretty hard when I was scrubbing the adhesive off the backside of the trackpad. I think I’ll bow out at this point and let Apple do the necessary repairs. (I’m not jumping with joy at the thought of opening the laptop up again myself.) Thanks for helping ID the issue though! — Will Gyory

jayne @jayne30390 crwdns2934065:0crwdne2934065:0: 1 · Answer 1 · 2020-06-06T19:51:07-07:00

Love to hear what Apple said. I have done some online research and it appears that incorrect placement of the ribbon between the trackpad and logic board can cause probs.

In my case I changed the screen and this did work for me though an old thread-

Roaring fan + super slow after Display/Lid replacement.

Best answer was-

I took it to the Apple Store and explained the situation, they ran their special diagnostic which told them that there was a malfunctioning temperature sensor in my computer, and the error code narrowed it down to my trackpad! Turns out when I was putting my computer back together I didn't properly connect the trackpad ribbon cable to the logic board. So all they did was open it back up, and re-seat the cable, turned it on and it now runs like a dream!

The computer was taking AGES and the fan was roaring up due to its own safety features, the computer detected a faulty temp sensor so it automatically heavily reduces the CPU clock speed (resulting in a VERY slow computer) and it spins the fan at max RPM as its assuming a worst case scenario of extreme temperature.

Hope this helps!! :)

Chris W @chrison600 crwdns2934065:0crwdne2934065:0: 1 · Answer 2 · 2022-05-17T17:05:29-07:00

Chris W @chrison600

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crwdns2931729:0crwdne2931729:0: Mud 17, 2022

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I hope it's ok for me to resurrect this thread. I've replaced the battery in a 2017 MacBook Pro 15, model A1707, and post-replacement the fans are running 100% and the CPU is being consumed approx 500% by kernel_task. This thread prompted me to download TG Pro, and I have used it to diagnose a possible hard drive temp sensor issue.

Is the hard drive temp sensor servicable? Could this simply be a ribbon cable issue?

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Did you ever figure out what the issue was?

crwdns2934271:0Mha 31, 2023crwdnd2934271:0 Yertletheturtleiam crwdne2934271:0

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amir farjoun @amirfarjoun crwdns2934065:0crwdne2934065:0: 1 · Answer 3 · 2022-12-04T19:06:41-07:00

amir farjoun @amirfarjoun

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crwdns2931729:0crwdne2931729:0: N'w 4, 2022

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Just to note I have the same problem after replacing a battery by myself only in my case, the pads and keyboards aren’t working, so I’m sure that I did something wrong I think with the cable that connects the touchpad..

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MacBook Pro 15" Retina Display Mid 2012 Repair

MacBook Slow with Loud Fans after Battery Replacement

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Update (01/12/2019)

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