Last night I went to plugin my headphones and listen to some music and lo and behold my headphones wouldn’t fit entirely in the jack, strange… I removed my headphones and went to take a closer look.
Apparently when your headphone jack is obstructed, in my case by a piece of plastic, there’s a tiny red light that lights up at the bottom of the jack. No, it’s not Skynet trying to take control of your computer.
In order to fix this, just take a toothpick or a paperclip and insert it into the headphone jack to clear whatever is blocking it.