Mac enters thermal loop after software update

Launch the Activity Monitor application. Select the CPU tab at the top and then select the %CPU column header and sort the column by descending ( v ) order. This will display, at the top of the list, those processes that are eating up the most cpu cycles and making your Mac work harder and creating heat.

When you know what is causing the Mac to work so hard, then you can start to work an fixing the problem.

Activity Monitor User Guide for Mac - Apple Support

Welcome and thank you for reaching out. 🤗

First, let’s see if this issue happens in Safe Mode:

1. Shut down your Mac.
2. Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
3. Select your startup disk. It's named Macintosh HD, unless you changed its name.
4. Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
5. Log in to your Mac. You might be asked to log in again.

If the strange behaviors do not occur, then it may possibly be a software issue.

If the issue doesn't continue in safe mode:

Leave safe mode by restarting your Mac normally, then try to reproduce the issue.

If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.

If the problem persists, then let’s try this:

• Software Update.
• Use Apple Diagnostics to test your Mac.

after my mac got its logic board replacement it stoped but again resurfaced

If none of my suggestions helped, then this could be a case of a faulty logic board. I recommend service.

Service Checklist:

• Mac service pricing.
• Check AppleCare Coverage.
• Get your Mac ready for service.

Service Appointment:

• Start a Service Request.

Contact Support:

• United States: 1-800-APLCARE.
• Contact Support.

Additional Support:

• Mac Support.
• Mac User Guide.
• Check Repair Status.

Good luck! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer

after my mac got its logic board replacement it stoped but again resurfaced after I did software update

It means that your Mac was faulty from the beginning. If you have a guarantee from the service that replaced the logic board, you can try to get that honoured. If not, you should try Apple Support for help. Its a physical problem, only an authorised service can remedy, if possible.

hodiee wrote:

Hi I have a mac issue which started after software update.

2-3 months back after I did software update my mac and thermal pressure would go into the loop of nominal -> modrate-> heavy -> trampling -> sleeping -> nominal each stage for 2-3 sec and this cycle will continue form 5sec to 30 min after opening the lead

my mac after my mac got its logic board replacement it stoped but again resurfaced after I did software update again.

Will you able to give me a solution for it as the cycles are quite periodic and after 5sec to 30min timeline mac works completely normally.

One additional thing this problem is even arises even when I open start up options as my mac goes to sleep in intervals at that time also. The tests and genius bar are giving no negative results in hardware.

What exact Mac...?

verify your software is up to date—

The current stable release of Tahoe including bug fixes, security updates is macOS 26.5.2

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support

unplug all non-essential peripherals when testing

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS

To trouble shoot further you can:

—A SafeBoot Start up your Mac in safe mode - Apple Support will sort many anomalies

Does a quick disk repair before it fully boots up, and certain system caches get cleared and rebuilt, third party system modifications and system accelerations are disabled temporarily.

Login and test. Reboot as normal and test. Caches get rebuilt automatically.

This test will tell you if third party interference; most extensions etc are not loaded in safe boot mode.

*** (if you are using a wireless keyboard with rechargeable batteries— connect the charging cable, this will make the wired keyboard successful Safe Boot your Mac.)

—Test issue in another user (or guest user) account Change Users & Groups settings on Mac - Apple Support

This will tell you if it a universal issue or isolated to your user/admin account.