MacBook Pro 14-inch restarts after long sleep sessions

LucDerLuc wrote:

I've run the suggested step by step but no success after all.

Unfortunate, but not unexpected.

In the diagnose fase I tested the "Hardware and Software diagnostic" and all items were checked green so can I assume this is also cannot a hardware problem? or can it?

The only useful diagnostic result is one which reports an error condition. Unfortunately today's Apple Diagnostics (including the service diagnostics) are a complete joke as they barely perform any actual tests on the system beyond checking for the presence of specific hardware components (basically a roll call), a very quick & basic memory test, checking the battery & charging system, and testing the cooling system....the latter is really the most reliable portion of the Apple Diagnostics.

Any other tips would be very appreciated.

The only remaining options are:

1. Perform a "clean" install by using the "Erase All Content & Settings" which will wipe out of customization & data on the internal SSD causing you to be greeted with Setup Assistant again
2. Perform a clean install of macOS by first using Disk Utility to erase the disk ("Volume Group"), followed by reinstalling macOS.
3. Perform a DFU Firmware Restore which resets the security enclave chip, system firmware, and internal SSD which destroys all data on the internal SSD & creates a new partition & file system while pushing a clean version of macOS onto the internal SSD.....this is a true & complete reset to factory defaults.

Option #3 is the best one to confirm whether you have a hardware issue. With any of these three options it is critical you:

• • • Do NOT sign into your AppleID or iCloud
    • Do NOT install any third party apps
    • Do NOT restore anything from a backup

Unfortunately Option #3 does require access to another Mac currently running macOS 15.7.3+ Sequoia or macOS 26.x Tahoe. Option #2 will in many cases be nearly as good as Option #3 and can be done without access to another Mac. Option #1 is the quickest option, but also the least conclusive since it leaves open possible file system issues as well as some other issues.

If you test your system under these very strict conditions and you still get those Kernel Panics, then you have confirmed a hardware issue (or most likely confirmed depending on which of the three options you used) which will require a hardware repair of the computer, or purchasing another laptop. A macOS bug is ruled out since we are not seeing any other wide spread reports with this type of Kernel Panic.

If you don't have any Kernel Panics under these strict conditions, then you can try restoring from a backup & using your computer normally. If the Kernel Panics return after restoring from a backup, then you should erase the laptop again, but this time only restore just the user data & home folder (uncheck everything else when restoring from a Time Machine backup including both system wide settings & settings within your home user folder).....manually reinstall your third party apps making sure they are fully compatible with macOS 26.3.1 Tahoe.

Unfortunately I think you will need to accept the fact that your laptop most likely has a hardware problem which will involve either having the laptop repaired or replaced.

LucDerLuc wrote:

Hello,

I bought a second hand Macbook Pro and it is restarting every time it has a longer sleep session. When I open the laptop again, I have to login and receive an error message saying the system had to be restarted.

Anyone has any idea? I've read reports saying it could be a hardware problem, some saying it's a Tahoe issue, and some suggesting Settings tweaks to fix the issue...

<Error log.log>

Here are my system details:

Macbook Pro 14"

2023

16mb RAM

Tahoe 26.1

Thank you!

The current stable release of Tahoe including bug fixes, security updates is macOS 26.3.1 - I would start there

Keep your Mac up to date - Apple Support

https://support.apple.com/guide/mac-help/get-macos-updates-mchlpx1065/mac

re: < LLC Bus error (Slave error) from cpu2 >

note: LLC Bus error (Slave error) on Apple Silicon (M1/M2/M3) is

a fatal kernel panic indicating a communication failure between a CPU core and the Last Level Cache, often caused by buggy drivers, incompatible USB-C/Thunderbolt peripherals, or faulty hardware.

unplug all non-essential peripherals when testing

—A SafeBoot https://support.apple.com/en-us/HT201262 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.

No insight or resolve—

Try the User Apple Diagnostics to test your Mac for hardware issues, ans see if it kicks out an error code.

https://support.apple.com/en-us/HT202731

panic(cpu 6 caller 0xfffffe003691969c): cpu6: LLC Bus error (Slave error)

LLC is Last Level Cache.

LLC bus errors on Apple silicon Macs refer to issues related to the Last Level Cache (LLC) bus, which can indicate a problem with the CPU or GPU communication or memory access. These errors may lead to system crashes or kernel panics, often requiring troubleshooting to identify the underlying cause.

That's a System-on-a-Chip Error. NOT software. NOT peripherals.

Transitory Memory problems have always been difficult to debug, unless the memory cell just dies. Flaky problems have always been even far more difficult.

You have a fairly clear indication of a memory-and cache error. That is far better evidence than what is usually available in these cases.

if you can undo the purchase, undo it.

if you can't, well, you have a work-around that seems to be working -- until it doesn't.

The actual "fix" is a mainboard repair-by-replacement.

I suspect it will be a hardware issue. You probably just found out why the laptop was being sold.