Screen Mirroring not working - checked all settings etc.

[Tómasz Zippermann]

It’s a two-month old iMac 2017, High Sierra.
I am trying to screen mirror to a Samsung TV with Airplay built in. (Also two months old).
There is no screen mirroring icon in the menu bar. I checked the box under preferences, displays.

When I click Bluetooth in the menu bar, the TV appears, so the iMac ‘knows’ it’s there.
Two iPhones and an iPad all screen mirror instantly with the tv, so the tv is not the problem.
Everything is on the same wifi network, all software is up-to-date.
Everything, inc modem has been rebooted.

There is no firewall or other security that I’m aware of.

I bought this setup largely for screen mirroring, and now it doesn’t work.

Apple is Hard to reach with Covid19 and now Easter.

I assume there’s probably a box somewhere deep down in settings that i have or haven’t checked, but I just don’t know. Any suggestions out there?

Many thanks
Tom

 

[waw74]

normally airplay is discovered over wi-fi
there is a newer "peer to peer" version that discovers over bluetooth, but then creates a wi-fi network to actually stream.
if you're on the same network, bluetooth shouldn't be used.

The iMac is also on wifi?
and you've re-booted ALL network gear, even "dumb" switches, wi-fi repeaters, and anything else that handles network.

in your TV settings, get the IP address.
on your Mac open terminal (in applications/utilites)
type the following, replacing the zeros with the ip of your TV

ping 00.00.00.00

you should get repeating lines of "64 bytes from ...."
hit ctrl-c to stop. And then quit terminal.
if you see the repeating lines, your computer and TV can reach each other on the network
if you get "request timeout" you've got network issues.

If the ping test works, this program will show you the broadcasts on your network. (it's how devices find airplay targets)
This link goes to the apple App Store. or you can search there for "discovery - dns-sd browser"

‎Discovery - DNS-SD Browser

‎Discovery is a utility that displays all of the Bonjour services available on the local network or on Wide-Area Bonjour domains. Use it to debug your latest program, detect computers connected to your network, or just keep tabs on what services are available. Perfect for network admins or...

apps.apple.com

Once you run the app, you should see an entry labeled ...

_airplay._tcp. (Protocol for streaming of audio/video content)

expand that, and every device that supports airplay should be shown.
you should see your TV, if not something is blocking the broadcast.

With the results of these 2 tests, we can probably narrow down the problems.

 

[Tómasz Zippermann]

normally airplay is discovered over wi-fi
there is a newer "peer to peer" version that discovers over bluetooth, but then creates a wi-fi network to actually stream.
if you're on the same network, bluetooth shouldn't be used.

The iMac is also on wifi?
and you've re-booted ALL network gear, even "dumb" switches, wi-fi repeaters, and anything else that handles network.

in your TV settings, get the IP address.
on your Mac open terminal (in applications/utilites)
type the following, replacing the zeros with the ip of your TV

ping 00.00.00.00

you should get repeating lines of "64 bytes from ...."
hit ctrl-c to stop. And then quit terminal.
if you see the repeating lines, your computer and TV can reach each other on the network
if you get "request timeout" you've got network issues.

If the ping test works, this program will show you the broadcasts on your network. (it's how devices find airplay targets)
This link goes to the apple App Store. or you can search there for "discovery - dns-sd browser"

‎Discovery - DNS-SD Browser

‎Discovery is a utility that displays all of the Bonjour services available on the local network or on Wide-Area Bonjour domains. Use it to debug your latest program, detect computers connected to your network, or just keep tabs on what services are available. Perfect for network admins or...

apps.apple.com

Once you run the app, you should see an entry labeled ...

expand that, and every device that supports airplay should be shown.
you should see your TV, if not something is blocking the broadcast.

With the results of these 2 tests, we can probably narrow down the problems.

Thank you very much for the detailed response, apologies for the delayed reply.

Both tests you suggested, the ping test, as well as the app were positive, meaning the tv and the iMac are ‘talking’ to each other, and the tv is airplay-capable.

The interesting thing is that, when I bought the iMac, it came with Catalina. At that stage, screen mirroring worked, however my Adobe programs no longer did. I therefore erased the HD and installed High Sierra.
I could reinstall and use my Adobe software (LR5), but mirroring doesn’t work.

This suggests it’s not a hardware fault of some kind, but rather a bug in High Sierra. I will contact Apple when I can, though I don’t hold out much hope.

If you have any further suggestions, I’d appreciate them very much.
In the meantime, I have bought the Samsung mirroring app, which works, but there is significant lag, and it is nowhere near as good as mirroring. It’s a workaround at best.

Thanks again for your help. I will keep trying.

Kind Regards
Tom

 

[waw74]

all software is up-to-date.

installed High Sierra.

The second quote make the first statement untrue.
The OS is software.

If you make a major change downgrading your OS by 2 versions, and then something stopped working.
You should mention the OS change when you try to get that feature working again.

It might work with an actual appleTV
High Sierra does say is supports airplay display, but the following link seems to say it won't

AirPlay system requirements - Apple Support

Learn which devices support streaming with AirPlay.

support.apple.com

Devices you can AirPlay 2 video from

• iPhone, iPad, or iPod touch with iOS 12.3 or later
• Mac with macOS Mojave 10.14.5 or later

 

[Tómasz Zippermann]

The second quote make the first statement untrue.
The OS is software.

If you make a major change downgrading your OS by 2 versions, and then something stopped working.
You should mention the OS change when you try to get that feature working again.



It might work with an actual appleTV
High Sierra does say is supports airplay display, but the following link seems to say it won't

AirPlay system requirements - Apple Support

Learn which devices support streaming with AirPlay.

support.apple.com

I take your point regarding downgrading the OS, but that OS - High Sierra, was up-to date and should screen-mirror.

I have a 2007 iMac running El Capitan and an iPhone 5 (from whichever year) and both have the function, so, in theory, there is no reason why this iMac won’t do it - with this OS.
Again, I think it’s a bug, and it’s pretty disappointing.
The beauty about Mac used to be that everything just works, but things have changed a bit.

If I get an answer from Apple I’ll write again.

Thanks again for your time.

 

[waw74]

most of the time updates for older versions are just security, and not new features

El Capitan is 2 versions before high Sierra.
iOS 10.3.4 - the latest a 5 can run - is the year before High Sierra.

You say both of those are working with your TV?
if so, your Mac with High Sierra should work.

Apple doesn't publicly talk about the security they use.
So I thought it could be an authentication problem with the newer TV.

Airplay is a catch all name, and works in different ways depending on what you're doing. (audio only, video + audio, streaming a file or mirroring your screen)
for the user, they all look mostly the same, but in the background each one is a bit different.
And the protocol has been updated a few times, most of the time it should be backwards compatible, but not always.

The first airports with airplay took forever to be spoofed, since they had hardware authentication, and people weren't able to go in and reverse engineer the handshakes required.
now it's all part of the software, so it's easier to go in and find the code that makes it work.
which is why you can make a raspberry Pi into an airplay2 target.

-----
now back to your problem

Have you tried a new user account on your Mac?
Just make a new one, and try mirroring from that one.
You can delete the test account once you're done.

are you doing anything "weird" with your audio output?
(beyond built in speakers, or speakers plugged into an audio jack)

Also you say "no firewall that you're aware of"
have you checked in the main settings app just to make sure it's off?

and just throwing this out there, it's not as clean,
but an old fashioned cable has a really low failure rate, and typically much better results.

There are also airplay receiver programs that run on Mac (and windows)
if you have another computer, you could install one of those as another test.
most have free trials that are time limited, that should be more than enough time to make sure it works.

 

[Tómasz Zippermann]

most of the time updates for older versions are just security, and not new features

El Capitan is 2 versions before high Sierra.
iOS 10.3.4 - the latest a 5 can run - is the year before High Sierra.

You say both of those are working with your TV?
if so, your Mac with High Sierra should work.

Apple doesn't publicly talk about the security they use.
So I thought it could be an authentication problem with the newer TV.

Airplay is a catch all name, and works in different ways depending on what you're doing. (audio only, video + audio, streaming a file or mirroring your screen)
for the user, they all look mostly the same, but in the background each one is a bit different.
And the protocol has been updated a few times, most of the time it should be backwards compatible, but not always.

The first airports with airplay took forever to be spoofed, since they had hardware authentication, and people weren't able to go in and reverse engineer the handshakes required.
now it's all part of the software, so it's easier to go in and find the code that makes it work.
which is why you can make a raspberry Pi into an airplay2 target.

-----
now back to your problem

Have you tried a new user account on your Mac?
Just make a new one, and try mirroring from that one.
You can delete the test account once you're done.

are you doing anything "weird" with your audio output?
(beyond built in speakers, or speakers plugged into an audio jack)

Also you say "no firewall that you're aware of"
have you checked in the main settings app just to make sure it's off?

and just throwing this out there, it's not as clean,
but an old fashioned cable has a really low failure rate, and typically much better results.

There are also airplay receiver programs that run on Mac (and windows)
if you have another computer, you could install one of those as another test.
most have free trials that are time limited, that should be more than enough time to make sure it works.

Well, it appears that you were absolutely correct about the OS possibly being the problem.

I did call Apple and was told very quickly that my particular tv will only mirror with Mojave, as it is more modern.
‘But my iPhone 5 is from 2012 and mirrors’ I countered, but to no avail.
Upgrade is the only way, apparently.

I still hold to my suspicion that this is probably a known glitch, but it’s easier to get people to upgrade than to fix it.

This will now prompt me to move all photos and videos away from Adobe and onto something different. Yes, I can upgrade Adobe but that takes me to a subscription model which I don’t want, and eventually the outdated software will catch up with me in another way regardless.

In the meantime, I will use my Samsung mirroring app with it’s painful 2 second lag. Using a mouse with it is not enjoyable...

Thank you very much for taking the time, and all your good suggestions. I didn’t try the last few, since I spoke to Apple first, and there’s probably no point going any further. I appreciate the help greatly.

Kind Regards
Tom

 

[Hrkporter]

It’s a two-month old iMac 2017, High Sierra.
I am trying to screen mirror to a Samsung TV with Airplay built in. (Also two months old).
There is no screen mirroring icon in the menu bar. I checked the box under preferences, displays.

When I click Bluetooth in the menu bar, the TV appears, so the iMac ‘knows’ it’s there.
Two iPhones and an iPad all screen mirror instantly with the tv, so the tv is not the problem.
Everything is on the same wifi network, all software is up-to-date.
Everything, inc modem has been rebooted.

There is no firewall or other security that I’m aware of.

I bought this setup largely for screen mirroring, and now it doesn’t work.

Apple is Hard to reach with Covid19 and now Easter.

I assume there’s probably a box somewhere deep down in settings that i have or haven’t checked, but I just don’t know. Any suggestions out there?

Many thanks
Tom

hello, I'm not sure how to fix that but I can suggest a mirroring app called LetsView. I always use it and haven't experienced any lag. The good thing is it is free so if you don't like it you can easily uninstall it from your device.