How to turn on red light (digital audio) inside of the 3.5mm headphone socket on macbook pros? So apparently many macbook pro models have a digital audio output hidden inside their 3.5mm headphone jacks.  Example.

I thought this was physically activated by the mini TOSLINK plug, but recently I installed Linux Mint (native boot) on my MBP and that red light came on and stay on.   

So I guess it can be controlled by software.

Anyone know how to activate it in macosx?   The only reason I want to turn it on is I think it looks cool.
Plug in a clear audio jack and you’ll have your red laser engaged and the sound muted. It’s controlled by firmware which is software, just harder to patch and mess with.