Overheated Circuitry

One of the things which I do frequently, is ‘walk around’, or, ‘use public transit’, with my disposable earphones plugged in to my Samsung Galaxy S9 Smart-Phone, and listening to music. These earphones are clearly not the ones, which had the AKG seal of approval, and which shipped with the phone. But this week-end marks the second heat-wave this Summer, when outside daytime temperatures exceeded 31⁰C, with direct sunlight and not a cloud in the sky. And under those conditions, the battery of my phone starts to hit a temperature of 42⁰. One of the facts which I know is, that Lithium-Ion batteries like the one in my phone do not tolerate temperatures exceeding 41⁰C.

A peculiar behaviour which has set in for the second time, during this second heat-wave of the season, is that the music I was listening to would either back-space to the beginning of the song, or skip ahead one song, or just stop. So, a catastrophic sort of explanation I could think of would be, that the entire phone, with its battery, is finally just having a meltdown. But, a second possibility exists, that merely the chip in the earphone-cord could be malfunctioning. After all, the little pod in the earphone-cord has one button and a mike, and it’s actually cheaper to mass-produce the chip that makes it work, than it would be to mass-produce other sorts of discrete components. One cheap chip could just be malfunctioning in the extreme heat, and not the entire, complex circuitry of the phone. (:1)

The earphones cost me about $15, while the phone is much more expensive than that.

But even if it was true, that only the little remote-control in the earphone-cord was malfunctioning, this can lead to impractical situations, because just random patterns, of unreal button-press-combinations, could also send the software of my phone into a confused state, and even so, if the circuitry in the smart-phone never malfunctioned. This behaviour could get misinterpreted by the security apps of the phone, let’s say, as though somebody had ripped the earphone-cord off my head, and thrown all my possessions around.

All that was really happening was that my music was no longer playing, as I was walking home normally, in the heat, with my overheated electronics. And when I got home, my actual phone never displayed any signs of having malfunctioned.

(Updated 8/17/2019, 17h50 … )

(As of 7/27/2019, 11h50 : )


Even though it might sound nice, just to suggest that maybe, the little chip in the earphone-cord, where the remote-control button and the mike are, malfunctioned such as to send spurious button-press-messages to the phone, the possibilities are not limited to that.

In reality, in order for real button-presses to be communicated, there also needs to be a functioning chip inside the phone, that receives these low-frequency voltage-codes, coming in over the mike-line.

When the phone gets 42⁰C hot, that chip could just as easily start to malfunction, as might the chip in the earphone-cord. And just because the phone is the more-expensive piece of hardware, that thought is not such a pleasant one for me.


(Update 8/17/2019, 17h50 : )

There is another explanation, for what might have happened to me on these two occasions. My phone has as feature an always-on display, which is configured to be on. This always-on display is able to control the media player on the phone, without requiring either that the regular lock-screen be summoned, nor that the phone be unlocked.

Well in extreme heat, I tend to perspire in my shirt quite strongly, and my perspiration may have been operating the controls of this media-player, by way of the phone’s touch-screen. And one reason for which I now suspect this is the fact that, even when I had no music playing, a few times I’ve unlocked the phone, to find that one of the icons in the first home-screen was highlit in a light-blue rectangle, as if I had selected it, but even though I had not selected anything intentionally.

So, the touch-screen could have been malfunctioning, and could have been doing so just because perspiration set it off. I have the ‘increase touch-screen sensitivity’ option set.

Yet, even though this idea may come as a relief, it’s still not a good idea for me, to operate the phone in a way, that will cause the battery to become hotter than 41⁰C.



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