High CPU temp / Max Fans Intermittent after battery & keyboard replace

[Tethu]

Hi Everyone,

I recently replaced a battery and a keyboard in a MacBook 2015 Pro and having issues with it randomly going to 100c and max fans as well. Mainly at bootup.

Ran Apple Hardware Test and reported no issues.

Nothing running that could cause it to heat up that much. Even going into the Apple Hardware Test it would rev up even before running the tests.

There wasn't this issue before replacing the parts that I'm aware of.

Any ideas on what could be the issue?

The customer said it was doing that before, but before I changed the battery I didn't see it happen.

Thanks heaps

 

[britechguy]

The customer said it was doing that before,

And they'd be in a much better position to tell you what the characteristic quirks of that machine were/are than you are. What possible incentive would they have to lie to you about this, specifically. Trying to fix something you didn't cause, and which the device's owner tells you has been characteristic is a waste of time and effort. You're done.

 

[Blues]

And they'd be in a much better position to tell you what the characteristic quirks of that machine were/are than you are. What possible incentive would they have to lie to you about this, specifically. Trying to fix something you didn't cause, and which the device's owner tells you has been characteristic is a waste of time and effort. You're done.

I partially disagree while the laptop may have been brought in for a keyboard and/or battery issue it is good for us as techs to identify and try to find the root of any suspicious behavior from equipment on our bench. Knowing it was a preexisting problem only tells me that I don't need to worry that I have done something wrong but I might try to find out what is wrong with it and determine the repair options. I would not preform said options without customer consent if it was not a reported issue when work was requested.

 

[britechguy]

@Blues

I can't disagree with you entirely, but nor can I agree with you entirely.

"Suspicious behavior" is pretty much always, to my mind, behavior atypical to a given machine as it was brought in. I have had many a machine (regardless of platform) that liked to do fast fans on initial boot for no apparent reason and where I have no reason to believe they have not always done so based on owner reports. I had a desktop like this (now recycled) of my own at one time.

If someone reports to me, "Oh, it's done that as long as I can remember," and it's this behavior in particular, I'm not wasting a single second of my time, or cent of their money, to chase it down afterward.

If you wish to ask a customer whether they'd like you to, there's nothing at all wrong with that. I just don't. There are "normal quirks" and once something has been identified as such for a given piece of hardware . . .

 

[Sky-Knight]

I've seen many laptops of all makes over the years behave that way and it always boils down to one of two possible issues.

1.) There's a missing firmware update to solve a sensor / fan controller problem. (make sure the BIOS is current!)
2.) The laptop was manufactured incorrectly, and the yahoo that did it left the metallic repair tape on the bottom of the CPU / GPU cooling assembly that's there to protect the component in shipping.

The latter is FAR more common in my experience, and it comes up A LOT here because well... Arizona is HOT! The only solution for the latter is a complete disassembly, removal of the cooling unit, remove the tape, clean all that gunk out of there, and properly compound and set the cooling system.

It wasn't all that long ago such systems would simply fail under warranty. But modern systems are so good at thermal throttling they'll survive for decades simply never actually running at full speed. Clients that get the repair done always report a HUGE performance gain, which isn't all that shocking when you figure the CPU and GPU have been at 50% or less capacity the whole time.

P.S. that's a two, possibly three hour repair... so watch some videos to get an idea of how much time you're going to have to sink in. And... Apple loves to use special adhesives to hold things together so you'll have to account for that too, and may have to purchase a heat gun to get it apart.

 

[britechguy]

Apple

And we are talking about a 2015 model.

 

[Sky-Knight]

And we are talking about a 2015 model.

Good point, so it might just be clogged up! Hair makes an annoyingly efficient filtration system when layered into a paddle fan and heat sink pair. Becomes an impregnable layer of lint very quickly and needs disassembly for removal. No amount of air blasting from the outside gets it all, though that will buy you some time.

 

[Blues]

@Blues

I can't disagree with you entirely, but nor can I agree with you entirely.

"Suspicious behavior" is pretty much always, to my mind, behavior atypical to a given machine as it was brought in. I have had many a machine (regardless of platform) that liked to do fast fans on initial boot for no apparent reason and where I have no reason to believe they have not always done so based on owner reports. I had a desktop like this (now recycled) of my own at one time.

If someone reports to me, "Oh, it's done that as long as I can remember," and it's this behavior in particular, I'm not wasting a single second of my time, or cent of their money, to chase it down afterward.

If you wish to ask a customer whether they'd like you to, there's nothing at all wrong with that. I just don't. There are "normal quirks" and once something has been identified as such for a given piece of hardware . . .

I was not trying to focus on this specific issue because high fan speeds at initial boot is to me not suspicious behavior too many laptops and desktops in my experience have done this. The OP did mention something about temps which that would be more concerning so that is something I might look into depending on timing and how long it reports the temps.

 

[britechguy]

I can't remember what the cpu is in these, but is 100 C even close to T(max)?

I find there is far too much concern about running hot when, if you check the specs, only involves running warmish, if that. Temp spiking at startup isn't unusual, and if it promptly resolves, is nothing to worry about.

 

[Blues]

Last I read on most CPU they thermal throttle around 90-100C

 

[Sky-Knight]

That's modern CPUs... in 2015 they throttled at 80C. I still don't like seeing anything over 80C in anything, and try to keep resting temps in the 40s.

Today you have to lookup the tolerance of the specific CPU in question, because AMD's APUs are tolerant of EXTREMELY high temperatures like most GPUs are. I still don't like them getting that hot, but at least you don't have to worry about damaging the chip. The rest of the stuff around the APU on the other hand...

 

[Blues]

2015 I was trying to keep my desktop CPU under 65C not as focused on laptops

 

[britechguy]

And that was 8th gen.

 

[Markverhyden]

Are you seeing warnings in the console logs? pmset -g thermlog will tell you if it's throttling the CPU when this is happening. Does it happen if you boot into recovery mode? When you said start up, is this during the actual POST and OS load or shortly after that?

 

[frase]

Is the battery a genuine apple battery, Apple can be pedantic.

Dreaded was ok before scenario, " HINDSIGHT HERO ALERT " always start systems in front of clients - I also use a video if I see suspicious behaviour of systems.

 

[Tethu]

Thanks guys for the replies. Got caught up with jobs and haven't had time to look.

Yeah its a 2015 MacBook Pro Retina. I ran tests on it before I changed things and didn't notice any issues like that.

It mainly does it just after typing in the password, or opening up programs randomly. Sounds like its going to take off. Does the same thing in safe mode.

Supposedly its a genuine battery from the place I got it from.

Ill check the console logs for that. I had a quick look before but didn't look that much into it.

We replaced the thermal paste and its overall calmed down a bit but still jumps up to 70 - 90 at odd times. I was just hoping the battery wasn't causing electrical issues if possible.

I think there was a heap of dust packed in there when I opened it. The most I've seen in a MacBook actually lol, if I remember correctly. Packed with lint and food. Had another one at the same time.

 

[sapphirescales]

And that was 8th gen.

No, that's 1st gen. Came out in 2010.

Try an SMC/PRAM reset. MacBooks are known for weird fan issues (along with other things) that can be fixed by doing an SMC/PRAM reset.

 

[Tethu]

Thanks Sapphirescales, I've tried them a few times but didn't make any difference.

 

[Tethu]

Thanks guys for the help. I think its working a bit better now. Cleaned out some old launch agents, McAfee Total Protection and some other things as well as change the thermal paste and doesn't rev up as much. Still a bit funny I think it might be some other issue because the charging cable takes a while to light up at times as well. Maybe logic board?

See what happens.

 

[overburnz]

Thanks guys for the help. I think its working a bit better now. Cleaned out some old launch agents, McAfee Total Protection and some other things as well as change the thermal paste and doesn't rev up as much. Still a bit funny I think it might be some other issue because the charging cable takes a while to light up at times as well. Maybe logic board?

See what happens.

Do you have access to another IPD flex cable? Maybe the trackpad cable is the issue there