Monterey 12.3.1 External Monitor/Display Issue - No Longer Outputting Signal

Apple - you have purposefully made this as hard f*****g possible to remediate because, unlike Windows, you are so arrogant in your OS updates (that you clearly do not QA at all), that you offer no downgrade option. ALL - this is the definitive solution that I employed THREE (3) WEEKS prior and I have not had ANY issues since then,

1. Backup your entire SSD via direct connected Time Machine. If you are like me with a large SSD, congrats, APPLE FORCED YOU TOO, to spend $500+ on on an Samsung 4TB external SSD (link) where you can use this USB-C to SATA connector (link) - all regular links to US Amazon; sadly, I have no referral code/links.
2. Download version 12.1 from this site (link)
3. Create a bootable install USB key (link)
4. Boot into safe or recovery mode and re-partition your entire SSD (this wipes the entire computer FYI, but is the ONLY OPTION APPLE has made available at all...)
   1. FYI - at this point I recommend that you just hardware your laptop into your router or switch and bypass Wi-Fi; its faster and easier.
5. Set up the "new laptop" as fast a possible; your going to wipe the entire "new"/"temp" user anyway.
6. Restore Mac from Time Machine backup (link) - delete that temporary user from the prior step; wait like 4 hours maybe (that's about how long my 3.4TB SSD restore took.
7. No more issues. For weeks, blissfully easy use once again.

** Apple, you owe me 20+ lost billable hours or work, at least many hours in lost work, and over $500 for having to purchase equipment only need to remedy your insane f*** u*; congratulations, QA and OS teams - those I doubt you were the ones who made the decision to focus on continually increasing levels of completely dumbs**t; but at least we have a **** ANIMOJI...might as well be your new logo.

Another user in another forum pointed this out to me and it... worked?

Disconnect your monitor

Unplug your monitor

Wait a minute or two

Plug your monitor back in

Connect your monitor

This... seems to have worked for me after trying all the more complex solutions (safe mode etc.)

So this is related to a previous long-standing bug with DisplayPort, which forced all of us to go into our monitor settings and switch from DP1.4 to DP1.2 so our external monitors would work. Apparently in "fixing" this bug, Apple decided that checking autonegotiation was redundant and the user needs to manually fix things.

The solution is to set your monitor to DP1.4. For a BenQ monitor, that is going to suck, because if you don't have a valid source input, it won't give you the display settings menu. You'll need to hook up a second computer to the monitor without macOS 12.3 so the monitor has a signal, then go into the menus (System -> Advanced -> DisplayPort) and switch back to DP 1.4. Your monitors will work.

I'm so happy to have had to troubleshoot this in the middle of a workday. It was problems like this that caused me to switch from Windows to Mac over twenty years ago.

Just chiming in. MacBook Air M1 12.3 made my external display no longer be detected. I am pretty unhappy, and I need this basic function for my job.

After a few frustrated google searches and many attempts to fix, I am still stuck. Please fix Apple.

NVM. I retract this statement. When I got back in this morning it was back to no external display (thanks Apple! Happy Monday!)

This needs fixing urgently, obviously. and no, I'm not buying an Apple display.

Same issue. HP32 4K.

Not a single solution worked - neither dropping to DP1.2, nor reconnecting monitor, nor resetting NVM and this kind of stuff.

Only working solution for now is connecting monitor via dockstation hdmi port. This is the only thing waking monitor up.

Neither usb-c to usb-c nor DP to usb-c cables are working anymore.

Using Mac 10+ years first time i come across something so basic being broken ... Total disaster that affects everyone and MUST BE fixed ASAP

Updated my iMac last night. Same issue. I have two LG monitors connected via DP through a CalDigital dock. The CalDigit connects to the iMac via a usb-c connection. After the update ALL monitors including the laptop were black and would display nothing.

I had to, as suggested by others, use the Settings menu on the monitor itself to swap to Display Port Protocol version 1.2. Then disconnect and reconnect the usb-c cable from the Mac. After a reset, and reconnect monitors work again. They were both previously configured for Display Port Protocol v1.4. So - something in the 12.3 update is messing up that protocol negotiation.

"After installing macOS Monterey, choose System Preferences from the Apple

menu , then click Software Update to check for the latest updates."

• Update macOS on Mac - Apple Support

//support.apple.com/en-us/HT201541

Some MacBook Pro models cannot see the update. Perhaps this

varies, due to hardware differences between build-model years.

• If an error occurred while updating or installing macOS - Apple Support

//support.apple.com/en-us/HT212526

[Page URLs could be loading slower today, depending on region.]

Perhaps some steps in above article need a review

or performed. However there are no guarantees in

this matter. Like 'volunteers' here, are fellow users.

Monitors may have a need for updated drivers(?)

Does the maker's website show anything new?

Sections, as: install after repairing startup disk; using

macOS recovery; Safe mode; erase & reinstall; &/or

perform basic troubleshoot/repairs.

Always good to have good backups, & maybe clones.

..I'm going offline again; to try & resolve local matters..

Perhaps to direct statements or questions to directly to Apple

through their 'Product Feedback' Portal may be more efficient?

• Product Feedback - Apple

//www.apple.com/feedback/

Hardware & Software 'product feedback' can follow tedious

paths; from main entry points, within the above website.

Certainly beats other attention getting schemes one may envision.

For those who sought and contacted Apple directly, they at least have

comfort ~ in knowing someone at corporate did see their comments,

expressions, and logged that report correctly. (Caps? considered rude.)

Anyone else, is Unlikely to see satisfaction, or get a reply from

Apple officially; in this user-to-user discussion forum format.

The bulk of online Support, with features (such as live chat)

etc; are available in regions where those are supported.

[Link to my above reply, to this 10+ page 'officially unanswered' rant.]

Monterey 12.3.1 External Monitor/Display … - Apple Community

When I upgraded to 12.3, I lost the ability to use two external monitors (Adding a second external display to my M1… - Apple Community). Apparently, the specs for my M1-iMac have never supported it, but it woked anyway until Universal Control was implemented. I had to spend $128.07 for a display adaptor and install DisplayLink. Apple's genius folk had solutions that didn't work.

I finally received the multiport adapter I'd been promised (this one) and guess what: My second monitor is consistently receiving a signal again - it doesn't matter if I use the HDMI cable directly or a DVI-HDMI cable with the adapter, it's working, even after multiple restarts! You can't use the adapter's USB-C port to connect the second monitor too though but only the HDMI port. Looks like Apple added something to MacOS 12 to keep people from using third party adapters to get them to buy the over-priced $70 one (or maybe they messed it up on accident and now simply don't want to fix it, who knows)! Everyone who's still got the problem: Ask your rep to send you that adapter too, so you can test it!

Same issue. being forced to upgrade to Monterey 12.3 due to company policy and suddenly second usb-c screen doesn't work.

Config: MAC Mini 2018 + 2 x USB-C connected LG 34WK95U Monitor

Tried the following although doesn't work at all.

• both monitor's display port already downgraded to 1.2 rather than 1.4
• separate the usb-c monitor connection - now connected to the far left and far right rather than side by side

Do not want to fall back to 1 x usb-c + 1 x hdmi/display port as the colour tone is not sync

Please fix it ASAP.

If both your secondary monitor and your Mac power cable are connected to the USB HUB then to your Mac, and your secondary monitor is NOT working and your machine's power source is Battery, try this:

1. Unplug your USB HUB
2. Unplug the power source cable from the USB HUB
3. Connect the power source cable to any USB Type C port on your machine - you should notice that your machine is now charging and is connected to the power adapter
4. Connect the USB HUB to another USB Type C port on your machine - you should notice your secondary monitor now turning ON
5. (Optional) Unplug the power source and connect it back to the USB HUB - I did this because I like my wirings clean looking :)

This is my first time encountering an issue with my Apply machine after an upgrade, and I am disappointed that Apple does not have any direct source of solution for an obvious bug.