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27" iMac used as a display
- Thread starter zoran
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If your 2010 iMac is still on High Sierra or Sierra, with its stock GPU, then yes, you can.
You'll need a miniDisplayPort to miniDisplayPort cable to connect them.
Do the PRAM reset on the iMac 2010 once or twice, then boot it normally to log-in screen.
At the log-in screen of the iMac 2010, just plug in the cable and the iMac will automatically detect the video in signal, turn it to the external monitor of the Mac Mini.
The speakers may work, too. Just select the audio output properly.
To get the iMac to display its own OS, just unplug the cable.
Issues: The iMac display will be at maximum brightness, fans run at full speed because of the heat.
This should not be a long-term setting.
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1. Why do i need to make the PRAM reset?
2. How do i make make the PRAM reset?
3. Since the mini doesn't really need to be far away from the iMac, then i guess its ok to buy the shortest MDisplay port to MiniDisplay port cable?
4. Regarding the issues, isn't there a way to bypass them? Cause both full brightness and full speed fans running are strong negative No-No's in doing this project.
2. How do i make make the PRAM reset?
3. Since the mini doesn't really need to be far away from the iMac, then i guess its ok to buy the shortest MDisplay port to MiniDisplay port cable?
4. Regarding the issues, isn't there a way to bypass them? Cause both full brightness and full speed fans running are strong negative No-No's in doing this project.
This looks like a more comprehensive guide: https://support.apple.com/en-us/HT2045921. Why do i need to make the PRAM reset?
2. How do i make make the PRAM reset?
3. Since the mini doesn't really need to be far away from the iMac, then i guess its ok to buy the shortest MDisplay port to MiniDisplay port cable?
4. Regarding the issues, isn't there a way to bypass them? Cause both full brightness and full speed fans running are strong negative No-No's in doing this project.
1. Why do i need to make the PRAM reset?
2. How do i make make the PRAM reset?
3. Since the mini doesn't really need to be far away from the iMac, then i guess its ok to buy the shortest MDisplay port to MiniDisplay port cable?
4. Regarding the issues, isn't there a way to bypass them? Cause both full brightness and full speed fans running are strong negative No-No's in doing this project.
1. I don't know. If something went wrong, like switching to Mac OS and TDM seems not working anymore, I would do a PRAM reset to turn it to default mode, which is automatically recognizing video input and go straight to TDM.
2. Turn-off the iMac, and when turn it back on (pressing the power button), press and hold CMD+Option+P+R for 3~4 minutes, until hearing the chime 3 times, then release the key press.
3. Good luck with that. Mine is 1.5m long.
4. To turndown Brightness, one must use software solution. Or just leave it at max brightness and get your eyes familiar to it. It was terrified at first, but after a day or two, I got used to it already.
From my Windows machine, it's possible to lower down color brightness from Intel HD Color Management (Calibration)
From Mac OS, you can use Brightness Slider.
For Fan Control, you can use Mac Fan Control. Log in to desktop, let Mac Fan Control running to lower down the fans, then start up/wake up the main machine.
The machine still get hot and the backlight still ages fast, as it has to run at maximum level.
The above answer came from 2 weeks using my iMac 2010 (in my signature) in TDM, as the display for my HP Prodesk 600G1 SFF.
Other things to remember:
1. Sleep/wake-up procedure: The iMac will not wake-up automatically when the PC wake-up first. You still need either a mouse or keyboard to wake the iMac.
When both machine go to sleep, if I wake up the PC, then the iMac, TDM will be off. When that happens, I must turn off/sleep the PC and turn it back on/ wake it up again to activate TDM safely.
You may use the Command + F2 or Command + Fn + F2 on a keyboard attached to the iMac. But I don't plug any keyboard to the iMac, so I prefer to control everything from the PC side.
2. Sound:
If you use the iMac's speakers, too, remember to increase the volume from the OS to 99% and control the volume from the other machine, otherwise it might sound very small.
No, it can't natively from Mac OS. I don't know if the Brightness Slider App offers control from keyboard. I just use my mouse.
There is no appropriate link to transfer the commanding signals for that, unlike a genuine old model Mac Display which has USB port connected to the Mac computer.
You can adjust the brightness using a keyboard connected to the iMac even while it is in TDM. This is because the iMac is still fully running and responding to the keyboard connected to it, otherwise the Command-F2 shortcut wouldn't work either.
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So those 2 issues u are referring to (especially the first), could it be due to the fact that you are using a Windows PC for your setup?
It was due to the fact that I hadn't use TDM very often, until recently.
And I don't have the Apple keyboard & mouse, either. I just have some cheap USB keyboard hooked up to the iMac.
Try it for yourself, if you already has the cables.
It's not that hard, not requires special skills, either.
You can even control everything by your Magic Keyboard & Mouse as well.
That's the issue right there. Using the original Apple keyboard that came with my 2010 iMac allows me to control the brightness just fine while it's in TDM. In other words: the iMac's display will not be stuck at full brightness - it's a matter of using the correct keyboard. It's a shame the iMac is so picky about that, but that's the way it is.
The source doesn't matter at all. And the backlight can be controlled using the original Apple keyboard that came with the iMac.
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I hear you. Sorry if I came across as grouchy or anything, I didn't mean to.
Not at all, thanks for your input.
I learnt from a Youtuber that TDM works on 21,5" iMasc with Thunderbolt 1/2 ports, too. (iMac 2012~2014)
Isn't it amazing?
I just don't wanna try it, the cost of TB2 cable + TB3 to TB2 adapter is just annoyingly high to me.
Sure, but TDM over Thunderbolt requires the source to be running macOS so it's quite a bit less versatile than TDM over Displayport. And it doesn't work with an M1 Mac as the source either.
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Hmm there seems to be an issue when wanting to use the mid2010 iMac as a display. A friend was telling me that if i want to connect a mini, then that mini needs to have the same OS or at least an OS before Catalina (if i remember correctly).
What prevents you from spending 5$ for a miniDisplayPort cable and try it on your machine?