Headless Mac Mini Hardware Hack

A few months ago I installed Ubuntu on my old 2009 Mac Mini (and apparently neglected to write about it), which went well except that it would only boot up properly if there was a monitor attached. For something that I’m using as a headless server, that amounts to a giant pain in the butt. We had a power outage last night and the thing once again didn’t boot up, so I finally did something about it.

Some quick searching led me to believe that using reFind or some other boot magic could solve the problem, but I didn’t feel like reinstalling my OS again. Luckily I came across this post about the same problem, in which the author used a simple hardware hack to convince the mini that it has a monitor.

I used 100Ω resistors because they were what I had on-hand, and it worked – reboots think they have a monitor, and the mac mini is useful as a headless server.  Total project time was about 20 minutes, most of which was spent trying to remember where I put my electronics.

Here’s a pin-out diagram showing which pins I bridged with the resistors: