MacMini Power Button and Indicator

From tunertricks.com March 10, 2005. As part one of the tech info posts on the GTi MacMini install, I wanted to put up a few pictures and a description of the process of moving the power button and power indicator. This is going to be pretty wordy, so click at your own risk…

The first issue I saw with the MacMini in a car environment was the fact that Apple located the power button for the computer on the back of the chassis. This makes total sense for them to do, since Macs are usually put to sleep instead of being shut down after each use. However, in a car, you really can’t let the computer sleep constantly without supplementing the vehicle’s electrical system in some way. I considered adding a second battery with a dual battery isolator relay to allow the MacMini to sleep when not in use without risking the possibility of draining the car’s starter battery, but that didn’t really seem to me to fall in line with the inherent simplicity of Apple’s computers. That would be a lot of additional stuff crammed into the vehicle with no real purpose but to avoid creating access to the power button somehow.

A second idea that was thrown around came from the guy who actually ended up shooting the finished photos of the car - Ryan Flynn. He suggested using a remote shutter release cable, which has a mechanically driven piston that would be perfect for pressing the power button on the back of the computer. Damn photographers…Pretty slick idea, but I was determined to see if the button could be removed and installed on the dash in a switch blank I had left over from the lack of heated seats in my car. I wanted the button within reach for obvious reasons, but I also really like that little power indicator that Apple screens on their buttons, and wanted it in plain view as well.

After perusing some early posts of people that were taking apart their new MacMinis, I noticed that the power button - as it apparently is on all current Macs (I took apart my iBook, at least, to confirm this) - is a simple two-conductor momentary pushbutton switch that tells the hardware to fire up. This actually made the process of relocating it (electrically, at least) pretty simple. Cracking open my brand new computer and getting the button removed without damaging it was a little more difficult - and stressful!

I really didn’t want to remove the entire board from the back of the computer (where the connectors are located), so a little gentle persuasion was employed (the button is mounted to a board that is adhered to the back of the case with a removable adhesive) to convince the button to leave its former home. The wiring for the button actually terminates in a connector that plugs into the main board, so I simply unplugged it and cut the original wires, extended them with a a Monster Cable two-channel 3 meter RCA cable and soldered this cable to both ends of the cut switch wires. The Monster Cable has four conductors color-coded and twisted into two distinct pairs (red/black and blue/black), so there would be no confusion on the other end of the cable when I reattached the button to the board. The extra two wires were used to extend the MacMini’s power indicator in the same fashion, as it also uses two conductors and plugs into the main board using an identical connector.

I then brought the cable through the hole left in the case where the power button originally resided and powered it up. That was a scary moment. I was pretty confident that extending the power button would be no big issue, as it either is making contact (on) or isn’t (off), but the power indicator LED could’ve not liked the extra resistance I was adding by extending its power supply cable by 3 meters. Luckily, Apple didn’t give the LED a weak dose of power from the main board, and the extra resistance doesn’t seem to have had any effect whatsoever on the LEDs brightness, and definitely has had none on its functionality.

Once the scary work was done and the MacMini was reassembled, it was really just a matter of drillng a couple of really clean holes in the factory switch blank and mounting the button and LED from behind with automotive-grade two-part epoxy to get the final result seen here. Now that it’s done, there’s really nothing quite like hopping in the car, starting it up and pushing that button to be greeted with the signature Apple startup sound. Problem solved.

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