iM 4,1-14,4 27” IMac as Monitor only?

[lostgonzoband]

I have a 2010 27” IMac that decided to go white screen and rolling beach ball on me. All I’ve read points to a bad drive.
I am pondering buying a Mini M2 and using the 27” as a monitor off the M2. Is this possible? What would I have to do to the current 27” to make this possible? Thanks!

 

[drrich2]

Use your iMac as a display with target display mode - Apple Support

Target display mode is a feature available with certain older Mac models.

support.apple.com

From that:

"24-inch and 27-inch iMac models introduced in 2009 and 2010
To use any of these iMac models as an external display:

• The iMac used as a display must have macOS High Sierra or earlier installed.
• The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
• The cable connecting the two Mac computers must be a Mini DisplayPort
  cable."

What you want is called Target Display Mode. I don't know if there's a workaround for what you want to do, but this is what some quick Googling turned up for me, and it's not promising.

 

[Bigwaff]

Target Display mode not an option. TDM won't work w/ 2020 or later Macs (i.e. M1/2/3 Macs)... or Macs running anything newer than macOS 10.15 Catalina... says so right in @drrich2 post.

 

[Juicy Box]

rom that:

"24-inch and 27-inch iMac models introduced in 2009 and 2010
To use any of these iMac models as an external display:

• The iMac used as a display must have macOS High Sierra or earlier installed.
• The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.

TDM won't work w/ 2020 or later Macs (i.e. M1/2/3 Macs)... or Macs running anything newer than macOS 10.15 Catalina...

This is correct for the Thunderbolt iMacs that are capable of Target Display mode, but not the Late 2009 and Mid 2010 27" iMac.

The Late 2009 and Mid 2010 27" iMac can be used as a display for AS Macs, or any Mac that is capable of using Display Port.

Actually, the Late 2009 and Mid 2010 27" iMacs can be used as a monitor to ANY device, regardless of being a Mac, Apple, or any other brand, that has Display Port out.

24-inch and 27-inch iMac models introduced in 2009 and 2010

That Apple support page has wrong info, the Early 2009 24" iMac does not have Target Display Mode support, at least not to be used as a display.

 

[Juicy Box]

There is a lot of bad information related to Target Display Mode, and at no fault to anyone on Mac Rumors, but because Apple's support page on it contains information that is incorrect.

I am pondering buying a Mini M2 and using the 27” as a monitor off the M2. Is this possible?

Yes, this will work fine, as long as your iMac still boots.

What would I have to do to the current 27” to make this possible? Thanks!

The iMac needs to work and boot up. I recommend using an external SSD or even a cheap flash drive as a boot drive, just to get it working and booting.

Then, all you need is a USBC to Mini Display Port cable, then plug the Mini Display Port side into the back of the iMac, and then the USBC side into the M2 Mac Mini, and it should connect automatically.

If it doesn't then you need to press "Command" and "F2" at the same time on the keyboard connected to the iMac, and it should display the Mac Mini. This also takes you back to the iMac if you need to.

Note: I have experienced the above keyboard press not work on keyboards that did not come with the iMac. I was using an Apple keyboard, just a different model and not the one that came with the iMac (I didn't like the one that came with it), and the button presses didn't work. I then used the one that came with the iMac and it worked.

 

[paardenkapper]

In any case I wouldn't want to rely on a dying iMac mainboard to grace me with displaying an image.

Another way to go would be: Look for the model of your LCD - it's probably some LG and find a suitable driver board on eBay and AliExpress. The advantaged would be lower power consumption and you had VGA, HDMI as seperate inputs.

 

[Nguyen Duc Hieu]

I have a 2010 27” IMac that decided to go white screen and rolling beach ball on me. All I’ve read points to a bad drive.
I am pondering buying a Mini M2 and using the 27” as a monitor off the M2. Is this possible? What would I have to do to the current 27” to make this possible? Thanks!

Replace the dead HDD and install High Sierra.
Power it up and let it boot to log-in screen.

Then plug-in a video source via the miniDisplay Port.

The iMac will auto-detect the video input and switch to Display mode.

It's simple like that for iMac 2010 27".