Hi everyone,
I've also encountered the same issue and hope the following will help with troubleshooting tests - but note that none of these fixed my issues so concluding that there is a Hardware/Software specific issue.
My issue is with my MacBook Pro M3 Max (purchased in December 2023) when connecting to a Samsung Odyssey G85SB monitor via a USB-C to Mini Display Port purchased on Amazon. This setup initially worked flawlessly for about a week but then suddenly stopped. I'm unsure if this coincided with an OS update.
Troubleshooting Steps Taken (All using Sonoma 14.3 for all MacBook Pro's):
1. Monitor and Cable Check:
- Tested the monitor and cable (USB-C > Mini DP) with a MacBook Pro M1 Max and two other MacBook Pro M3 models; all connected successfully.
- Tested my MacBook Pro M3 Max on the same monitor model at Best Buy (thank you), indicating the issue is specific to my device.
2. MacBook Pro M3 Max Tests:
- Attempted to force display recognition by holding the option key in display settings; no success.
- General test of the USB-C ports - Connections using USB-C to USB-C and HDMI to HDMI worked normally.
- USB-C ports functioned correctly with other devices like storage and scanners.
3. Operating System Investigation:
- Performed a complete erase and clean install of Sonoma 14.3, including testing in Safe Mode; the issue persisted.
- Restored my Time Machine backup on another MacBook Pro M3 (non-Max variant), and the display connection (USB-C > DP) worked, suggesting a hardware or model-specific software issue.
4. Hardware Assessment by Apple:
- Sent my MacBook for repair; Apple replaced the Logic Board and Touch ID board, but the issue remained post-repair.
- Finally today - received a brand-new replacement MacBook Pro M3 Max; encountered the same issue even before updating the OS, indicating the possibility of a M3 Pro Max model-specific problem.
Conclusion and Next Steps:
After extensive testing and interaction with Apple Support and seeing the other posts on this thread, it seems there might be a specific issue with the Sonoma OS and the MacBook Pro M3 Max model, as other M3 models function correctly.
If anyone from Apple Engineering sees this - I'm happy to work with you to troubleshoot this further or if anyone has any other ideas please reply.
Not the best way to spend the holidays!!
