The mysterious XF86AudioPlay issue

According to this reddit post, headphones with TRRS jacks can signal play/pause/whatever by fiddling with the resistance of the microphone line. So my guess is that whatever dirt just so happened to be triggering that over and over!

(the other way, which Apple uses, is apparently to send a high frequency signal over the mic line, which is harder to decide but means you don't interfere with the actual mic signal)

edit: https://source.android.com/docs/core/interaction/accessories/headset/plug-headset-spec indicates that play/pause is signaled via a short, and TRRS locates mic next to ground. So there was probably something conductive shorting the two, and the two seconds was likely just denouncing.

A recent anecdote on unexpected key activations.

I tried replacing the keyboard on my aging laptop (ASUS GA503QM). The original was N-key rollover, the replacement was 2-key rollover, with ghosting (yes, that issue that I thought was essentially fixed a couple of decades ago). 2KRO is unbearable for a touch-typist, because you regularly have at least three keys depressed at a time. For example, having h, e and Space all active would also trigger F11—so typing the word “the” would normally get a spurious F11 activation.

Anyway, the most fascinating part was that various combinations would activate keys that don’t even exist, such as numpad 0. That doesn’t even make sense. (Mashing the keyboard would put it to sleep, and also leave some keys in a broken state until you rebooted, or, I think, successfully untied its knot, hitting specific keys to unravel it by one stage, in order. Though that was possibly at least partly software bug.)

So I went back to the original badly-worn, oft-spongy, Left-hasn’t-worked-for-two-years, e-is-a-mite-unreliable keyboard. As punishment for trying to replace it, both Control keys stopped working a week later, so now I’ve remapped RShift to RCtrl (but alas, Fn+RCtrl was Menu and I can’t get that on RShift—oh how I wish laptop manufacturers would let at least unknown Fn combos come through as a regular modifier). And Fn+F5 stopped working in the couple of months between then and now too, though Fn and F5 independently still work fine.