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64 votes

MacBook Pro (2018) stopped detecting external monitor

Similar issue with Philips monitor, MacBook Pro 2017 TB, and Digitus USBC-DP dongle. My solution: Remove the power cable from the external monitor, wait 5-10 seconds, put it back in.
felice's user avatar
  • 1,014
39 votes
Accepted

How to enable sound on MacBook when connected to second monitor via HDMI?

macOS is outputting sound over HDMI and has decided that volume should only be changed on the device receiving the sound. If you want the audio to come out of the monitor, adjust its volume directly (...
beiju's user avatar
  • 506
31 votes

Force external display refresh rate

When you're on the new Macbook Pro (post 2017), and you've connected your external display to one of the ports on the right side of your MacBook, the refresh rate settings dropdown may be disabled. ...
mxdi9i7's user avatar
  • 411
31 votes
Accepted

How to stop sound output switching to a monitor when it gets plugged in?

I have multiple devices I connect to my mac and for some they had the same issue. The work around (or actual fix) is to open 'Audio MIDI setup' in your Applications>Utility and: Click + in the ...
norcal johnny's user avatar
20 votes
Accepted

MacBook [Pro] or iMac - how many displays, what resolution/frequency?

This may not be the only available resource on this topic, but it is a comprehensive & reliable one... EveryMac, as the name suggests, has information on every Mac model ever made [also iPhones, ...
Tetsujin's user avatar
  • 116k
19 votes

External monitor flicker / signal loss

I've had a support case at Apple for over a year about this issue. They finally answered that it's a software issue and they are looking into it. We have spent a lot of money in our business on ...
Daniel Lindblad's user avatar
14 votes

Can I do 4K@60hz with my early 2015 MacBook Pro Retina?

I have a similar device (Early 2015 rMBP with 16 GB running macOS Sierra 10.12.6) and can confirm that it will power an external 4K display at 60 Hz - it's supposed to power two external displays at ...
TheValK's user avatar
  • 141
14 votes

MacBook doesn't remember Screen Orientation

I had this same issue. So the solution is: The external monitor should be connected. From App drawer open ColorSync Utility. In Devices column, select display and Under Displays select your external ...
Charanjeet Singh's user avatar
13 votes
Accepted

MacBook Air occasionally freezes when external monitor is connected

More than likely, the issue is, in fact, your Mini DP to HDMI adapter. The AmazonBasics Mini DisplayPort to HDMI Adapter adapter that you listed is a passive adapter (notice nowhere do they say &...
Allan's user avatar
  • 103k
13 votes

MacBook Pro (2018) stopped detecting external monitor

This might seem silly but this worked for me (also better to exhaust all options): I use a dock connected into the thunderbolt port. My charger connects into the dock and so does the monitor (dp to ...
iammrmehul's user avatar
12 votes

How to enable sound on MacBook when connected to second monitor via HDMI?

Try to open System Preferences -> Open Sound -> Click Output -> Switch devices to headphones or speaker.
Elaine 's user avatar
  • 119
11 votes

Force external display refresh rate

I can only change the refresh rate for the 4K TV connected to my MacBook Pro (15-inch, 2016, Big Sur) by following these steps: Open System Preferences, then click Displays. option+click the Scaled ...
richardsun's user avatar
11 votes

MacBook [Pro] or iMac - how many displays, what resolution/frequency?

@Tetsujin answer includes very good third party options. But I often find direct information is better instead of going to a third party. So get information directly from Apple... Navigate to Apple'...
user7886229's user avatar
  • 10.1k
9 votes
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Can I prevent OS X from resizing and moving windows when sleeping while attached to an external monitor?

Go into the menu on your external monitor. If there's an option that allows one device to toggle the power on the other via HDMI, make sure this is deselected (honestly, I don't think this will have ...
JDQ's user avatar
  • 360
9 votes
Accepted

Does USB-C to HDMI take more processing power than direct USB-C to DisplayPort?

Technically speaking, your Macbook has two Thunderbolt 3 ports. From Apple.com: Two Thunderbolt 3 (USB-C) ports with support for: Charging DisplayPort Thunderbolt (up to 40 Gbps) ...
Allan's user avatar
  • 103k
9 votes
Accepted

Connecting Mac Book Pro 2017 to 2 Projectors via USB C

According to Apple's Technical Specifications 13” 2017 MacBook Pro is able to support 2 external displays. Simultaneously supports full native resolution on the built-in display at millions of ...
Wilfred Smith's user avatar
8 votes

Volume Keys not working with HDMI audio on mac OSX Lion?

As SoundFlower is extremely outdated and not actively maintained. I've started looking for a better solution. I highly recommend this, works pretty great on my LG monitor: https://github.com/...
JoniVR's user avatar
  • 181
8 votes
Accepted

MacBook 4K/60Hz adapter is working directly, but not via USB-C hub

The reason that when you plug in your (known to be good/working) USB-C to HDMI video adapters into USB-C hubs is because the USB-C hubs don't pass the video signal that originates from the MacBook ...
Allan's user avatar
  • 103k
8 votes

External monitors show blank screen until restart

The video signal on the Thunderbolt connection on your MBP is actually Display Port so you are actually going from Display Port to HDMI. I am not a fan of converting signals because it's flaky at ...
Allan's user avatar
  • 103k
8 votes

How to stop sound output switching to a monitor when it gets plugged in?

You just need to specify a preferred audio device once and the Mac system will remember your choice and won't switch the next time. Open System Preferences -> Sound. Opt-in "Show Volume in menu bar", ...
Mclamee's user avatar
  • 81
8 votes

How do I use my macbook pro as a monitor for my HDMI device?

You're looking for a "HDMI Video Capture" device. Super cheap and works wonderfully ! It turns your HDMI signal into a USB webcam basically. I've used this one with success (I'm not ...
Taiko's user avatar
  • 181
8 votes
Accepted

How to audio out to iPad Pro when connected to HDMI?

Unfortunately not. As far as iOS is concerned, HDMI works at the device level, and responds according to the EDID of the display device - if the display announces via its EDID it handles audio as well,...
BentonQuest's user avatar
7 votes

How do I reset/clear my external display settings in 10.9?

Neither of the above two answers has solved the problem. Maybe I can move the ball forward a couple of inches ... I, too, clicked on the wrong resolution for my external monitor and now I can only use ...
August's user avatar
  • 505
7 votes

Can 2013 MacBook Air output to 2560x1080?

I believe the problem is your HDMI cable - it's not capable of displaying a resolution of 2560x1080. In other words, it's pre-HDMI 1.4 specification. (Also, the link provided to the cable in the ...
Allan's user avatar
  • 103k
7 votes
Accepted

Best option for connecting MacBook Pro with USB-C to monitor with DisplayPort and HDMI?

I would go for USB-C to DisplayPort directly. That would be one relatively inexpensive ($20 to $40 US prices) cable to do the job. Since your display won't charge the MacBook and do video over a ...
bmike's user avatar
  • 237k
7 votes

External monitor flicker / signal loss

I just had this issue with a 2016 MBP and a Samsung 28" U28E590 Display. Tried a bunch of things, but what seemed to work was switching the monitor to use to HBR1. The setting was in the monitor's ...
user278185's user avatar
7 votes

How to stop sound output switching to a monitor when it gets plugged in?

I made an app for this. It allows you to pin input/output so it cannot be changed for every particular set of connected devices.
Pavel S.'s user avatar
  • 189
7 votes

Dell WD15 Dock with 2017 MacBook Pro

This is a hardware limitation. I tested Dell WD 15 with my 2016 Macbook Pro 15. I used VGA and HDMI to connect my 2 monitors with Dell WD15 but Mac recognized both monitors as one. Later, I ...
Him's user avatar
  • 71
7 votes
Accepted

Send "soft power off" signal from a Mac via HDMI to a TV

How can I make a TV (a Sony W755C in my case) do a "soft power off" (same as when pressing the ON/OFF on the remote) by sending HDMI signals from a connected Mac? Unfortunately, you can't. ...
Allan's user avatar
  • 103k
7 votes
Accepted

What's wrong with HDMI?

HDMI is an AV (Audio/Visual) interface that is designed for consumer devices. DisplayPort is focused on the computer industry. As such, one functions better in a compute environment than the other. ...
Allan's user avatar
  • 103k

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