128C temperature sensor on heatpipe outgoing air.

[Lakazaki]

Hello everyone.

Recently my 2015 MacBook Pro fans have been going crazy as well as the cpu throttling. Going into a temp sensor app indicates that heatpipe 2,3 & heatpipe outgoing air has a temperature of 128C (see photos) which is causing the kernel to think the mac is overheating and the fans are on 6500 rpm all the time. I can’t even use FaceTime at all because it needs to “cool down” when it’s already freezing where I live.

I’ve used a third party app for the fans but the machine is unusable because of it being so laggy. Is there any
software workaround it to make the kernel not think its overheating or is there an easy hardware fix
which I can do? Any help would be much appreciated.

- I’ve tried SMC/Pram reset
- I’ve tried cleaning the logic board with 99% isopropyl alcohol.
- I’ve put in a new battery + trackpad and issue still persists even in safe mode and recovery mode

Hardware Diagnostics indicates codes: PPN001, PFM006 & NDC001

Sometimes these codes disappear briefly and Mac runs perfectly for about 10-15 mins before cpu overloads once again!

Any expert help will be greatly appreciated!

 

[januarydrive7]

I had a similar issue affect my beloved 15" 2012, which turned out to be moisture damage to the SMC.

You mentioned cleaning the logic board, so I'm guessing you're comfortable with a bit of disassembly. Take a slow, careful look to see if you have water damage anywhere. You might even download circuit diagrams for your model and get an idea of where you ought to be looking. Best of luck

 

[elvisimprsntr]

High "kernel_task" CPU usage and hyperactive fan, even after hardware repairs and OS reinstall

Hi all, For the past 2-3 months I've been unsuccessfully dealing with a problem with my MacBook Pro (Retina, 13-inch, Late 2013, Mavericks). The fan runs very loudly, "kernel_task" consistently uses ~300% of the CPU, and the computer runs very slowly as a result. After erasing the hard drive...

forums.macrumors.com

 

[Lakazaki]

I had a similar issue affect my beloved 15" 2012, which turned out to be moisture damage to the SMC.

You mentioned cleaning the logic board, so I'm guessing you're comfortable with a bit of disassembly. Take a slow, careful look to see if you have water damage anywhere. You might even download circuit diagrams for your model and get an idea of where you ought to be looking. Best of luck

Yes, I’ve watched some YouTube tutorials and I’m familiar with disassembling the Mac. I’ve done it and could not find any signs of corrosion. I don’t recall spilling anything on my Mac either, I’ve attached some photos of the logic board which I’ve recently cleaned. Do you see anything peculiar anywhere on the Mac? Sorry, I’m no expert with logic boards.

 

[eRondeau]

The 128C just doesn't jive with the other temperatures, or the ~4W power consumption. And that temperature would seriously melt plastic. I think you've got a faulty sensor, or possibly whatever fan control software you've got running is giving a faulty reading back to the system.

Delete the fan control software for starters, and make sure you get all the kernel extensions and other segments of code it added. Reboot in Safe Mode, then again normally. If all else fails, backup and reinstall MacOS. (I don't say that lightly BTW). Good luck!

 

[januarydrive7]

Yes, I’ve watched some YouTube tutorials and I’m familiar with disassembling the Mac. I’ve done it and could not find any signs of corrosion. I don’t recall spilling anything on my Mac either, I’ve attached some photos of the logic board which I’ve recently cleaned. Do you see anything peculiar anywhere on the Mac? Sorry, I’m no expert with logic boards.

Honestly, it's really hard to tell with those pictures --- you'd need to look a lot closer than these pictures can show you. Additionally, sometimes you wouldn't even be able to see issues directly (which is why a good place to start would be downloading diagrams to see which components _might_ be involved), but usually you will when you start to look closer.

The 128C just doesn't jive with the other temperatures, or the ~4W power consumption. And that temperature would seriously melt plastic. I think you've got a faulty sensor, or possibly whatever fan control software you've got running is giving a faulty reading back to the system.

Delete the fan control software for starters, and make sure you get all the kernel extensions and other segments of code it added. Reboot in Safe Mode, then again normally. If all else fails, backup and reinstall MacOS. (I don't say that lightly BTW). Good luck!

This is almost certainly not the software causing this issue -- those monitors simply report what the SMC is reading of various temperatures monitored around the board. This is a common issue that shows up when temperatures are simply not being reported correctly due to circuitry issues, typically due to a short somewhere from liquid damage.

 

[eRondeau]

Yeah, the decimal number "128" being hexadecimal "0080" which I'm sure has some significance as a signed integer. If it read 123C that would seem as a more-likely believable number, but 128C is the equivalent of an error code.

 

[Webster's Mac]

I'm pretty sure 128C is what it reads if it can't read from a sensor. Most likely a sensor is bad. What happens when you run Apple online diagnostics (Option D at startup)?

 

[Lakazaki]

I'm pretty sure 128C is what it reads if it can't read from a sensor. Most likely a sensor is bad. What happens when you run Apple online diagnostics (Option D at startup)?

Hardware Diagnostics indicates codes: PPN001, PFM006 & NDC001

 

[Webster's Mac]

Those indicate issues with power management, SMC, and the camera. See here: https://support.apple.com/en-us/HT203747

 

[Webster's Mac]

Have it ever come into contact with liquid? Any power outages/surges?