When your Mac’s display out stops working
I landed in San Francisco at around 10pm, hit the hotel in Santa Clara by 11.30pm, crashed, and woke up to give my tutorial at 9am. By 8.45am, I couldn’t get my 12″ MacBook to display out via HDMI or VGA to the projector, so I ran back to the room to get my 15″ rMBP instead.
Later on, I ran the Apple Hardware Test. Or what it’s called now, Apple Diagnostics. Everything came back just fine, which seemed odd.
The best fix seemed to then be resetting the NVRAM. That didn’t improve things, so I had to reset the System Management Controller (SMC), and voila! everything seemed to work thereafter.
In the years of using Apple hardware, I have to think this is the first time I’ve had to do this. I guess the presentation pro-tip here is always carry a backup presentation device (I might going forward get the relevant dongles for the iPad to run a presentation too).