Trouble using Target Display with 2012 iMac as a display for PC laptop

[Icaras]

Well looks like I have to work remotely and rather than just using the screen on the PC laptop my company has issued me, I was hoping to utilize my iMac as a thunderbolt display. I've read Apple's own support document and I know my 2012 iMac supports it. The PC laptop is a Lenovo ThinkPad T490s and does indeed support Thunderbolt 3.

So I went and bought the Apple Thunderbolt 3 to Thunderbolt 2 adapter and a Thunderbolt 2 cable, connected both, and pressed Command + F2, but it doesn't work. I am using an Apple Magic Keyboard as well. Is there something I'm missing? Anyone know what might be going on with my setup?

 

[Juicy Box]

Target Display Mode only works for Mac to Mac, it doesn't support not Mac devices.

 

[DLary]

The Target Display mode for older iMacs that use displayport works fine with non-Apple computers. The newer thunderbolt iMacs only work with other macs.

 

[nshinka]

Unfortunately Thunderbolt iMacs will only work with Macs for target display mode.

 

[AdamJohnG]

I have just got a Late 2009 27" iMac working as external monitor for a Toshiba laptop. Taken me a bit of investigation but it is working. I have it connected HDMI to Mini DisplayPort via an adaptor cable - The trick is that there are many DisplayPort/Mini DisplayPort to HDMI cables, but they are all unidirectional - what is needed is an HDMI to Mini DisplayPort adaptor cable, they are not cheap (circa €45) and have a USB plug to power the adapter electronics.

The one I purchased is:

StarTech.com 3ft (1m) HDMI to Mini DisplayPort Cable 4K 30Hz - Active HDMI to mDP Adapter Converter Cable with Audio - USB Powered - Mac & Windows - Male to Male Video Adapter Cable (HD2MDPMM1M)

StarTech.com 3ft (1m) HDMI to Mini DisplayPort Cable 4K 30Hz - Active HDMI to mDP Adapter Converter Cable with Audio - USB Powered - Mac & Windows - Male to Male Video Adapter Cable (HD2MDPMM1M)

www.amazon.com

So far it is working perfectly. I can keep the iMac always on and CMD+F2 changes from running as a Mac to being external display of the Toshiba Laptop. No need to unplug the adapter cable - Just close laptop, push back under the iMac, and start using the iMac.

One thing to take note is that I seem to remember that to go into Target Display mode one had to use an Apple keyboard, I am not sure if that is true, as I use the original BT Apple keyboard that came with the iMac.

As an aside, may I say that the Late 2009 27" iMac Core2Duo with an SSD and 12GB Ram still works well as a basic internet/MS Office work horse - I do have a 2018 Mac Mini with a Dell 38" widescreen monitor for more serious work.

 

[r6mile]

I have been using Target Display Mode to connect my 27" mid-2010 iMac to my work PC laptop for a few months now and it's been working very well. I had to buy a MiniDisplayPort to USB-C cable, not cheap but cheaper than a monitor! I didn't know this was not possible with the 2011 TB model, makes me glad to have the 2010 iMac.

 

[AdamJohnG]

Good to know that there is another solution. This Toshiba only has HDMI and good-old VGA! - Showing it's age!

Yes the cables are not cheap, but way cheaper than a cheap monitor and none compare well to our old iMac screens.

Just brought this up as there are quite a few posts on different threads here saying that this is impossible!

 

[Juicy Box]

Just brought this up as there are quite a few posts on different threads here saying that this is impossible!

Were the posts referring to TB iMacs?

iMacs with the MiniDP that support Target Display Mode can be used with non-Macs, but the OP is using an iMac with TB, which AFAIK cannot be used in Target Display Mode with a non-Mac.

 

[AdamJohnG]

Some of the posts have said that TB Macs can't use Target Diplay Mode with PCs, but others have generically said that Target Display Mode only works with Macs, which is what the Apple Support also generally suggests.

I had not found a clear explanation as to how to connect an HDMI PC to the iMac and what was required. I also had read a few posts of people who had failed when trying with a Mini Display Port to HDMI cable.

I was just explaining how I had made it work.