Clever folks that they are, the Apple folks designed the headphone jack on MBPs to take both standard headphones and digital audio out. It detects which jack is plugged in by the shape (differently-shaped jacks trigger different switches inside the port) and automatically disables the internal speakers when an external audio out device is plugged in.

The problem with this design turns out to be the switches inside the port. Because they’re apparently entirely mechanical, once a switch has been triggered by plugging a device in, it doesn’t release control of audio to the default speakers until it’s been triggered off. And, it turns out, if you unplug your standard headphones at the wrong angle, it’s possible to toggle on the digital out. The digital out is transmitted by an optical signal, hence the red light from the headphone jack.

Fascinatingly, plugging in a different audio device (aka, headphones) overrides the digital out, but only until that device is unplugged, at which point the digital out takes control once again.

So how do you resolve the situation? Manually.

Take a toothpick or another small hard, non-metal object, and trigger the digital-out switch, which is in approximately the 6-7 o’clock position in the port. Metal objects don’t seem to cause any damage, but when I tried using screwdrivers to trigger the switch, the port detected them as headphones and turned off the digital out only when the screwdriver was in the port. A toothpick did the trick within seconds.

I’m well acquainted with the standard techniques of password security, and I always use medium to long passwords with a combination of upper and lower-case letters, and numbers. I’m not quite comfortable yet with using special characters in my passwords, so I don’t use though. I also like to have unique passwords for accounts that I want to keep secure, so having a good way to come up with new passwords and remember them is necessary.

My main technique for generating passwords is to find a short quotation or song lyric I like that includes a number (or a word with a numeric homophone) and use its initials as a password. For example, one of my now-deprecated passwords was “anc2ptw”, for the Matthew Good Band lyric “A new color to paint the world.”

Another important technique for protecting one’s passwords, of course, is making sure that you’re the only one who knows them. This is normally relatively easy, but here’s where I fell through last week. You see, I normally have multiple terminal windows and multiple instant message windows open at the same time, and I am not always as cautious as I could be about what text goes in what window. Pinging someone “ls” or “exit” is embarrassing, but not problematic.

No, the problem came mid last week when I accidentally pinged my friend Inga one of my more important passwords instead of entering it into the prompt I intended. My advice to you: don’t do this. It’s a bad idea.

I went ahead and changed my password. Here I learned another lesson about choosing passwords, one that isn’t frequently mentioned:

When selecting a password, you should always make sure that it’s something that you can type. By which I mean, think a bit about balancing letters on both sides of the keyboard. Muscle memory will help save you from typos in common words, but a string of random letters is going to take much longer to settle in. Forgetting your password is one thing; mistyping it two out of every three attempts because of, say, a four-character cluster of home-row characters for the left hand is downright embarrassing.

I have yet another new password now. And it seems to be working out well for me so far. Here’s hoping it will work out for me.