imac keeps shutting down after I put it to sleep

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imac keeps shutting down after I put it to sleep

My imac keeps shutting down after I put it to sleep. How do I fix this?

panic(cpu 0 caller 0xffffff8005151439): Sleep transition timed out after 180 seconds while calling power state change callbacks. Suspected bundle: com.apple.iokit.IOGraphicsFamily. Thread 0x23d223.

Backtracing specified thread

Panicked task 0xffffff93b50d19a0: 321 threads: pid 0: kernel_task

Backtrace (CPU 0), panicked thread: 0xffffff8eebb9c548, Frame : Return Address

iMac 27″

Posted on Sep 10, 2026 7:37 AM

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Answer 1

Top-ranking reply

kaz-k

Level 9

52,862 points

Sep 10, 2026 8:42 AM in response to JHH126

Hi,

Your iMac keeps having a kernel panic (a fatal system crash) after sleep because a connected device, a background driver, or a hardware component is failing to wake up properly.

Try to following tricks if kernel panic stops.

1) Unplug all external hard drives, USB hubs, Thunderbolt docks, and non-Apple peripherals.

Keep only the Apple keyboard and mouse connected.

Put the iMac to sleep and test it. If the crash stops, one of your accessories or its cable is causing the sleep/wake failure.

2) Start up in Safe mode and see if it's still caused kernel panic.

3) resetting NVRAM and SMC if it fix it up.

4) Running Apple Diagnostics if it reports any error.

If it reports any hardware error, I think you should call Apple Support or Apple Authorized Service provider with error number to fix it up there.

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Answer 2

Sep 10, 2026 1:39 PM in response to JHH126

Post the complete Kernel Panic log here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar. Post several Kernel Panic logs if possible. Kernel Panic logs are located in the "/Library/Logs/DiagnosticReports" folder and the "ProxiedDevice-Bridge" folder (name may not be 100% accurate and only exists on T2 systems) or one of the "Retired" subfolders there. Kernel Panic logs usually have "kernel" and/or "panic" in their file names.

Also, run the third party app EtreCheck and post the complete report here so we can examine it for possible clues.

How to use the Add Text Feature When Posting an EtreCheck Report - Apple Community

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