After upgrading to macOS 26 yesterday on my Mac Studio M1 Max, my display stopped working. I am using a 65" Vizio TV as a display and when I plug that same exact HDMI cord into a computer monitor it displays correctly. Any ideas on why this is not working? Thanks!
Mac Studio, macOS 26.0
Update: I purchased a high quality USB-C to HDMI cable, and that made no difference. The TV/monitor was still missing in the Display settings and it automatically attempts to mirror the TV as an extended display. Worst yet, there is no way to stop mirroring/extending. What I wound up doing as a band-aid was installing a utility called "BetterDisplay" which has a setting to force a discovered TV to be seen as a "computer monitor". That totally fixes the forced mirroring of your TV connected via a USBC or HDMI cable. I switched back to a normal hdmi cable to free up a Thunderbolt port and all is good!
Update: I purchased a high quality USB-C to HDMI cable, and that made no difference. The TV/monitor was still missing in the Display settings and it automatically attempts to mirror the TV as an extended display. Worst yet, there is no way to stop mirroring/extending. What I wound up doing as a band-aid was installing a utility called "BetterDisplay" which has a setting to force a discovered TV to be seen as a "computer monitor". That totally fixes the forced mirroring of your TV connected via a USBC or HDMI cable. I switched back to a normal hdmi cable to free up a Thunderbolt port and all is good!
I tried to ask chatgpt, initially asked me to do a "clean boot". I'm using MacBook Pro M1.
Option 1 (Clean boot): Shutdown, wait a few seconds at least 30 seconds. Hold the power-on button until you see "Loading startup options", then click "restart". - This didn't work for my laptop.
Option 2:
In terminal, run
sudo rm /Library/Preferences/com.apple.windowserver.displays.plist
Then restart and reconnect the display. "This forces macOS to rebuild display preferences".
I did option 2 but instead of restart I did shutdown and did the option 1 again. It worked, I can now extend or mirror to my external monitor. Not sure if option 2 alone can fix it. Hope this helps. Please share your experience.
After updating to the 26.1, I am now fully working. The TV as display is back in action. Yay!!! :)
Updating to Tahoe 26.1 resolves the issue on my MacBook Pro M4 and Mac mini M1. To clarify, my setup is as follows: LG G2 TV is connected to a Pioneer A/V receiver via an HDMI cable, and both the MacBook and Mac mini are connected to the A/V receiver with HDMI cables as well.
Only other thing that I can think of to try, is a USB-C to HDMI adapter.
for some examples:
USB-C Digital AV Multiport Adapter - Apple
https://www.amazon.com/Anker-Aluminum-Pixelbook-Compatible-Thunderbolt/dp/B07THJGZ9Z
While I am crossing my fingers and waiting for a software fix, I have been using Airplay/Screen Mirroring to my TV as a temporary workaround. It is not the best because it is laggy with video and the colors are washed out but it is usable for the time being.
I went into the room with the two monitors and tested the behaviour after the last OS update, and now it's working again for me. I had to unplug the HDMI and plug it back in again, and switch down to 30hz, but maybe it would have worked anyway if I'd waited a bit. Anyway, I can work with it now.
Test a different HDMI cable.
Preferable the shortest possible, Certified Ultra High Speed 8K HDMI cable.
for a good example: > https://www.amazon.com/dp/B08M9HND4F/ref=sspa_dk_detail_0?
Same here. Smart SBID‑7086R-P connected to MacBook Pro M1 via HDMI. The Mac recognizes the monitor, but the monitor does not recognize the Mac. Last week it still worked with the old macOS.
Switching to USB-C shows the same error pattern. Another Smart SBID‑7086R-P reacts the same way. It really seems to be due to macOS26.
Restarting, getting a new cable, or using a USBC hub does not fix the problem. Like I posted earlier, I've reported the problem to Apple Care rep, and he'd promised to pass the case to Engineering. It would be good, if other people could do the same, i.e. call Apple Care and report the issue.
I've downgraded my Mac mini to macOS Sequoia, and I'm now able to use my LG TV (via a receiver) as an external monitor once again.
I participated in the Beta and provided an Apple team with *many* details of my setup (briefly: 16-in. MBP M1 Max, HDMI to Grundig TV). The 26.1 beta release resolved my issue completely, and in the 26.1 release my issue remains resolved. Hopefully Apple is getting details and feedback from others with different configs to resolve the problem soon. I can’t speak for Apple, but the team working with me seemed exceptionally motivated.
I actually can't use a different cable, because it is embedded in the wall/attic... If the same cable worked for the previous five years, and it still currently works with a computer monitor [plugged into the exact same end] then it has to be some sort of a bug or software issue, right?
Well, I would like a solution to use the hardware that I already have purchased and has been working. Buying a bunch of new cables/etc just to see if they work is not a realistic answer.
Do you all think that the Apple developers monitor this 'community' to see what bugs need fixing? :)
macOS_user_892 wrote:
Do you all think that the Apple developers monitor this 'community' to see what bugs need fixing? :)
As far as I know, Apple does not do much monitoring of these forums, except to moderate them. Occasionally, I have seen posts telling people to contact Apple Support directly, but that's about it.
There is the Product Feedback page:
TV as display not working after macOS 26
