iM 4,1-14,4 27" 2010 iMac as "target display" works!

[Mark.g4]

You can not use 2010 21,5 inch model:

 

[pshufd]

Hello! I've been browsing the forum, and I got the impression that you are more knowledgeable about these issues than Apple's official support. I hope you can help me!

I have a MacBook Pro (Retina, 15-inch, Mid 2014), and I spontaneously bought an iMac (21.5-inch, Mid 2010) with High Sierra, hoping to use it as a backup computer and an external monitor. Later, I bought an Apple Thunderbolt Cable and quickly realized it was a mistake. After speaking with official support, I purchased a DisplayPort Cable, but when I connect it, there is no response.

I tried testing Luna Display, but the result was not suitable for comfortable work. Additionally, the connection is made through shared Wi-Fi, ignoring the connected cable.

After reading the forum, I got the impression that not only the operating system and year of release matter but also the screen size. It seems that everything works fine with a 27-inch screen, but there is no mention of a 21-inch screen.

Is there any way to connect my computers using DisplayPort or some other cables? I'm trying to understand what the problem might be and if it's even possible. Perhaps there are some hacks or workarounds. Thank you in advance!

According to this Apple support article, https://support.apple.com/en-us/HT204592 the 24 and 27 inch iMacs in 2009 and 2010 have Target Display Mode available via MiniDisplayPort cable.

The only way I know how to do would be to use screen sharing.

 

[Nguyen Duc Hieu]

Hello! I've been browsing the forum, and I got the impression that you are more knowledgeable about these issues than Apple's official support. I hope you can help me!

I have a MacBook Pro (Retina, 15-inch, Mid 2014), and I spontaneously bought an iMac (21.5-inch, Mid 2010) with High Sierra, hoping to use it as a backup computer and an external monitor. Later, I bought an Apple Thunderbolt Cable and quickly realized it was a mistake. After speaking with official support, I purchased a DisplayPort Cable, but when I connect it, there is no response.

I tried testing Luna Display, but the result was not suitable for comfortable work. Additionally, the connection is made through shared Wi-Fi, ignoring the connected cable.

After reading the forum, I got the impression that not only the operating system and year of release matter but also the screen size. It seems that everything works fine with a 27-inch screen, but there is no mention of a 21-inch screen.

Is there any way to connect my computers using DisplayPort or some other cables? I'm trying to understand what the problem might be and if it's even possible. Perhaps there are some hacks or workarounds. Thank you in advance!

Hack is workable if you convert the LCD panel to a standalone one. But the cost will not justifiable your effort. Better search for a 27" iMac. It's much simpler with 27" iMac.

 

[Amethyst1]

According to this Apple support article, https://support.apple.com/en-us/HT204592 the 24 […]

There’s no 24” 2009/2010 iMac, and only the 27” 2009/2010 iMacs have Target Display Mode.

 

[pshufd]

There’s no 24” 2009/2010 iMac, and only the 27” 2009/2010 iMacs have Target Display Mode.

Apple's article is wrong then.

 

[Amethyst1]

Apple's article is wrong then.

Yup. To clarify, only the 2009/2010 27" iMacs will do DisplayPort Target Display Mode. All 2011≈2014 non-Retina iMacs will do Thunderbolt Target Display Mode.

 

[HoSpeLL]

iMac 2011 27'' (Ventura with Nvidia Quadro K4100M) target display is not working for me with thunderbolt. Just bought original cable and tested with both my macbook pro's (High Sierra & Ventura)

 

[pshufd]

iMac 2011 27'' (Ventura with Nvidia Quadro K4100M) target display is not working for me with thunderbolt. Just bought original cable and tested with both my macbook pro's (High Sierra & Ventura)

Supposedly the iMac has to be run with High Sierra or earlier.

 

[cyberstudio]

Just wish to thank the OCLP team. I can still use my Mid-2010 27" running Monterey as a monitor with a DisplayPort output from a Thinkpad running Linux. OCLP revived the Target Display Mode feature.

2011+ requires a Thunderbolt connection (not DisplayPort). What I do not understand was that a Mac-to-Mac connection is supposed to be a Thunderbolt connection.

 

[Sr.Freson]

Just wish to thank the OCLP team. I can still use my Mid-2010 27" running Monterey as a monitor with a DisplayPort output from a Thinkpad running Linux. OCLP revived the Target Display Mode feature.

2011+ requires a Thunderbolt connection (not DisplayPort). What I do not understand was that a Mac-to-Mac connection is supposed to be a Thunderbolt connection.

Hi did you do that?

Currently using a Imac mid 2010 27" with a Macbook Air M1. I'm only able to use target display mode with the imac if it's running High Sierra. As soon as it boots on Monterrey (via OCLP) target display mode stops working (I only get a black screen for a second, and then it gets back to Monterrey OS.

I'm using a usb-c to mini displayport cable.

Thanks and greetings from Spain

UPDATE : I've just tried pressing several times cmd+f2 and some of them I get target display mode working! What it's never working is to get the audio out though the IMAC (What works properly in high sierra).

 

[Dalechy]

Hi All
Good News! I bought a usbc- mini displayport cable and have now got my Macbook Pro M3 connected to the screen of my 2010 27" imac

 

[builtinbc]

Just wish to thank the OCLP team. I can still use my Mid-2010 27" running Monterey as a monitor with a DisplayPort output from a Thinkpad running Linux. OCLP revived the Target Display Mode feature.

2011+ requires a Thunderbolt connection (not DisplayPort). What I do not understand was that a Mac-to-Mac connection is supposed to be a Thunderbolt connection.

I tried this on my mid-2010 27" iMac running Sonoma 14.3.1 under OCLP 1.4.2, from a 2019 Intel MacBook Pro that is not running OCLP (using a USBCele DisplayPort 4K to USB-C/Thunderbolt 3 adapter and mini-DisplayPort cable that had worked for Target Display Mode when both Macs were on High Sierra, of course without OCLP), but I could not get it to work. A couple of times, after pressing Command-F2 on the iMac keyboard, both displays went black briefly, but no sync occurred, and the iMac does not show up as an external display choice on the MBP. I tried the Apple-recommended fixes if TDM doesn't work (logging out of the user account, rebooting both machines, disconnecting and reconnecting the cable, etc), but still no luck. Have you upgraded your OCLP and MacOS on the iMac, and if so, does Target Display Mode still work for you?

 

[cyberstudio]

Sorry but I didn't use that Mac any more. I had planned to upgrade but no energy to do so. Still on Monterey.

 

[J9O]

Just following this thread as I want to know whether I could use a mid-2010 imac 27" running high sierra as an external display via a usb-c/displayport cable from an M3 macbook air. I phoned apple support and a was told "no", and in no uncertain terms (put me off Apple a bit - they might want to work on that)! However, the reports on this thread suggest both the apple support article, variously referenced, and the apple support staff, might be inaccurate/wrong.

For clarity, does anyone know with relative certainty whether a mid-2010 imac 27" high sierra can be used as an external display for a 2024 macbook air m3 running sonoma?

Any steer much appreciated - thanks!

 

[redheeler]

Just following this thread as I want to know whether I could use a mid-2010 imac 27" running high sierra as an external display via a usb-c/displayport cable from an M3 macbook air. I phoned apple support and a was told "no", and in no uncertain terms (put me off Apple a bit - they might want to work on that)! However, the reports on this thread suggest both the apple support article, variously referenced, and the apple support staff, might be inaccurate/wrong.

For clarity, does anyone know with relative certainty whether a mid-2010 imac 27" high sierra can be used as an external display for a 2024 macbook air m3 running sonoma?

Any steer much appreciated - thanks!

It can be. At some point after High Sierra, and also with newer models of iMac, Apple stopped supporting Target Display Mode so the Apple employee you talked to probably thought that applies to everything now.

 

[J9O]

It can be. At some point after High Sierra, and also with newer models of iMac, Apple stopped supporting Target Display Mode so the Apple employee you talked to probably thought that applies to everything now.

Many thanks!

 

[redheeler]

Also to add, if Apple's reasoning is that a current Mac on Sonoma doesn't specifically support the iMac in TDM, this doesn't matter since the 2010 27" iMac in TDM emulates a generic DisplayPort monitor. Anything that supports the DisplayPort protocol it uses can connect to it, doesn't even have to be an Apple device or OS. Current Macs and Sonoma support the DisplayPort protocol as it was and is used by many different external monitors.

 

[Nguyen Duc Hieu]

Just following this thread as I want to know whether I could use a mid-2010 imac 27" running high sierra as an external display via a usb-c/displayport cable from an M3 macbook air. I phoned apple support and a was told "no", and in no uncertain terms (put me off Apple a bit - they might want to work on that)! However, the reports on this thread suggest both the apple support article, variously referenced, and the apple support staff, might be inaccurate/wrong.

For clarity, does anyone know with relative certainty whether a mid-2010 imac 27" high sierra can be used as an external display for a 2024 macbook air m3 running sonoma?

Any steer much appreciated - thanks!

It doesn't matter what kind of device you send video signal from. As long as it uses DisplayPort protocol, your (and my) iMac 2010 27" with the stock GPU in High Sierra will detect the signal and turn to Target Display Mode automatically.

 

[builtinbc]

I tried this on my mid-2010 27" iMac running Sonoma 14.3.1 under OCLP 1.4.2, from a 2019 Intel MacBook Pro that is not running OCLP (using a USBCele DisplayPort 4K to USB-C/Thunderbolt 3 adapter and mini-DisplayPort cable that had worked for Target Display Mode when both Macs were on High Sierra, of course without OCLP), but I could not get it to work. A couple of times, after pressing Command-F2 on the iMac keyboard, both displays went black briefly, but no sync occurred, and the iMac does not show up as an external display choice on the MBP. I tried the Apple-recommended fixes if TDM doesn't work (logging out of the user account, rebooting both machines, disconnecting and reconnecting the cable, etc), but still no luck. Have you upgraded your OCLP and MacOS on the iMac, and if so, does Target Display Mode still work for you?

Update: I was able to put the iMac in TDM on a few occasions just by repeatedly pressing Command-F2 on the iMac (original keyboard), but only after about 20 tries. It worked well with the iMac as an extended display at its default screen resolution, and exited TDM properly after pressing Command-F2 once. Playing with the screen resolutions didn't improve the chances of success. Holding down Command-F2 for a prolonged period does not work. And a few times, first the iMac's and then the MacBook Pro's screen went black for about 10 seconds, and it was obviously trying to sync, but couldn't.

 

[builtinbc]

Hi did you do that?

Currently using a Imac mid 2010 27" with a Macbook Air M1. I'm only able to use target display mode with the imac if it's running High Sierra. As soon as it boots on Monterrey (via OCLP) target display mode stops working (I only get a black screen for a second, and then it gets back to Monterrey OS.

I'm using a usb-c to mini displayport cable.

Thanks and greetings from Spain

UPDATE : I've just tried pressing several times cmd+f2 and some of them I get target display mode working! What it's never working is to get the audio out though the IMAC (What works properly in high sierra).

I had the same experience with infrequent success with Command-F2 in enabling TDM. Were you ever able to figure out a way to get the Macs to sync reliably after just one attempt?

 

[builtinbc]

I had the same experience with infrequent success with Command-F2 in enabling TDM. Were you ever able to figure out a way to get the Macs to sync reliably after just one attempt?

I also couldn't get audio to play on the iMac when I tried that just now. But I don't need that, just a reliable way of trying to enable TDM for the iMac's display. I guess I can reinstall High Sierra on the iMac and try that, thank