Does the 21.5" iMac support TDM or not?

It is ALL non-Retina iMacs from 2011 onwards, it is a matter of having a Thunderbolt port, and nothing to do with screen size!

There is confusion, and some posters say that no 21.5" iMac can support TDM, despite other posters saying they are already using it!

Reading something and getting confused is fine, but reading something and getting an answer that is the opposite to what is being said is a rare and astounding skill :-)

The website, several people have commented that they are already using TDM on non-Retina 2011 or newer 21.5" iMacs...

To all the folks going "Why are you responding to an old thread; the thread is still relevant, several people have come here for enlightenment regarding the subject, and have left with more confusion because 'intelligent' 'experts' are stating 'facts' that are the reverse of the information the product manufacturers are giving.

Why do people state as fact something that is so obviously wrong?

Ambiguity Perfected!

"21'5-inch iMac as an external display, simply connect it with a Thunderbolt cable to another Mac with Thunderbolt"

a late 2009 doesn't have a Thunderbolt 3 port, it has a mini-display port

Hey KingDawg, I'm trying to achieve the same thing. Bought a thunderbolt to thunderbolt official Apple connector and connected the MiniDisplayPort on my late 2009 iMac 21.5 inch to a 2015 MacBookPro thunderbolt.

When I plug in and perform the CMD+F2 nothing happens?

Now I have read the fine print on the support pages it seems as though its not possible on this version of iMac but just wondering has anyone got this working?

Does anybody know any other ways of using an iMac as a second screen?

Hi Marbaque. I had exactly the same scenario.

Unfortunately the table Mike refers to does not explicitly say that the 21.5" is not supported so I purchased the thunderbolt to thunderbolt adaptor just in case.

It did not work. Which is a massive shame and frustrating tbh - particularly as the larger size screen has the support built in 😟

Other people seem to have hacked the old iMac to make it work but of-course you would lose it as a standalone Mac.

Take you almacaw for your response. I was going to get the same cable just to try, because I read a comment that specifically mentioned TDM working on the 21.5 2009 model, but everywhere else comments say it doesn't work.

I am sorry you found out the hard way man.

Seriously? The table lists models that CAN be used as displays, the 2009 iMac isn't listed. The table is clear even if it gives an answer you don't want to hear.

iMac (Retina 5K, 27-inch, Late 2014) and later iMac models can't be used as Target Display Mode displays.

It's very simple really. Here is the support page for TDM which includes which Macs work and which don't.

Use your iMac as a display with Target Display Mode - Apple Support

Read the support document Use your iMac as a display with Target Display Mode - Apple Support Pay particular attention to the table of iMac models you can use as a display.

You are welcome

does target display mode work on iMac late 2009 21.5 inch

Actually tthere's two new responses on here sorry though didn't mean to offend you replying to the newest questions

I am in the same situation as you are and beckcarioca. Has it finally worked for you? That is successfully use the late 2009 iMac 21.5" as external display to MacBook Pro using MDP-MDP cable?

Why do you say it works with your late 2009 21.5" iMac?

Apple says it can't!

Am I missing something here?

Thanks!

I have a late 2009 21.5 inch iMac with mini display port

---- I want to connect it to a new 2017 MacBook Pro using target display mode