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How to convert your old Mac into an external monitor using Luna Display
Enhance your workspace with Luna Display’s Computer-to-Mac Mode, enabling you to extend your display to any Mac. Looking for a larger screen setup? Repurpose an additional Mac as a second or extended display for your primary Mac or PC. Breathe new life into your Older Macs by using them as external monitors. This mode supports various combinations of Mac models, including:
- iMac + MacBook Pro
- iMac + Windows PC
- MacBook + MacBook
-
Mac mini + MacBook (using the MacBook as the main display for the Mac mini)
Minimum Requirements
-
Luna Display (USB-C)
- Primary Computer
- Mac running macOS 10.13 (High Sierra) or later
- Or a PC running Microsoft Windows 10 64-bit, Build 1809 or later
- Secondary Mac (to be used as external display)
- Mac running macOS 10.13 (High Sierra) or later
-
Optional but highly recommended for performance
- For Macs: USB-C to USB-C Cable or Ethernet Cable
- For PCs: Ethernet cable
Step 1: Plug in your Luna Display
Once you have your Luna Display, you’ll need to take the dongle and plug it into your primary Mac or PC.
The Luna Display dongle must be plugged into a USB-C port that supports Thunderbolt or Display Port. While most Mac USB-C ports offer this compatibility, there are exceptions with the M-series Mac Mini and Mac Studio. On these devices, only the USB-C ports on the back support Thunderbolt or Display Port, whereas the front ports do not. For PCs, the situation is less straightforward. To ensure compatibility on a PC, make sure to plug the dongle into a USB-C port labeled with a Thunderbolt or Display Port icon. See the chart below for examples.
Supported USB-C ports
Step 2: Connect your iMac to your computer using a cable
While Luna Display does support Wi-Fi connections, we strongly encourage you to use a cable connection when using the Old Mac as a display. Driving the 5K iMac as a monitor requires a lot of bandwidth, so you’ll get the most reliable and consistent performance when wired.
Connecting your Old Mac using a cable to another Mac
Connect your secondary device (Old Mac) to your primary device using a USB-C to USB-C cable or an Ethernet cable for best results.
Connecting your Old Mac using a cable to PC
Unfortunately, USB cables cannot be used with Mac to PC setup. Luna display recommends using an Ethernet cable. Plug the ethernet cable into the secondary Macs ethernet port (incase it does not have the ethernet port, you can use an Ethernet to USB-C adapter)and then plug the other end directly into your PC’s ethernet port.
Step 3: Download and launch the software
All the necessary hardware is plugged in now, so the final step is to load up the necessary software on your computers:
On your primary Mac or PC, download and open the primary Luna Display app
Next, on your secondary Mac, download and launch the Luna Secondary app. Downloads are available here.
Step 4: Use your Old Mac as a monitor!
At this point, your secondary Mac and primary computer should automatically detect each other and the secondary Mac should be configured as a monitor!
There are a few more settings you should configure. In particular, highly recommend enabling Retina Resolution so you get a crisp picture!
That’s it! 😄 You’re all done. You can now enjoy your old Mac as an external monitor.
If you need extra help in understanding the process or have other inquiries, please feel free to reach us helpdesk@macfixit.com.au