Can I use an external monitor for macOS recovery mode?

Thanks to a solution provided in another thread by ElectronDebt, here is what you can try:

1. Plug in the external monitor

2. Plug in the power adapter

3. Boot up while holding Command-R to start recovery mode

4. After it boots up and gives you the grey pattern screen on the external monitor, close the lid of your Mac

5. The external monitor will become the main display and you can complete the recovery

I can tell you from personal experience supporting my organizations Macs, that this can be a very difficult task. Sometimes it is just impossible, but with a 2017 model it should be possible. It could take you multiple attempts.

I would even suggest trying with an external wired USB keyboard. Power on the laptop, then immediately after hearing the startup chime, close the Clamshell lid while also holding down the Option key on the external keyboard. Hopefully you will see the Apple boot picker menu (aka Option Boot screen) on the external display. If you do, then press either Command + R for local recovery mode, or Command + Option + R for Internet Recovery Mode.

H3rC0rn5 wrote:

However, I don't know what the option key is on a normal keyboard, "ALT"?

Yes, even on the Mac, the Option key is actually Option/Alt (at least some years ago). The Windows key (or Super key) acts as the Command key.

The frustrating thing is that Apple's wifi selection for command+option+r only displays on the built-in screen.

• Luckily there is a 1mm gap between the 5/6 purple vertical bars that overlay the screen, which was just enough space to select the correct wifi router (almost 30 wifi signals all locked) in a very click-and-try manner.

I didn't think of that part since I typically use a wired Ethernet connection for so long just for that very reason.

typing Command-BrightnessDown

toggles the sense of "Mirror Displays" to put the same pictures on both displays. Doing it again goes back to extended desktop.