Anker SoundBuds Slim problem

[Shivam_Shah]

As some of you might remember, I put out a review of my Soundbuds Slim in March last year (found here). I’ve used it every weekday since then and it was great until February this year.
While I was sitting on my university campus working on my stuff, I noticed that the loop get hot around the back of my neck. I removed the earbuds and felt but couldn’t feel much heat. So put them back around my neck and felt the heat again in a bit. Pulled out again and felt it was quite hot. When I inspected them, I noticed there were 2 tiny holes on the loop somehow. I had the earbuds around my neck all day and had used them earlier in the day so I know I didn’t pierce them in any way.

This is the general area on the earbuds themselves

These two show the two holes (sorry for the poor quality)

I didn’t feel it was safe to use them so I put them back in the pouch and when I got back home, I wrapped a piece of paper around the holes because it felt a little wet. After about 30 minutes, I checked the piece of paper back and saw some liquid of oozing out of the holes.

That’s the color of the liquid (rusty brown)

I contacted Anker customer support and they said it wasn’t covered in warranty (understandable since it had just crossed 18 month warranty) but gave me an option to send them back on my expense and they would provide a new pair free of cost (also understandable and probably something no other company would do).

I didn’t get a chance to ship it back because of my classes and then coronavirus but wanted to see if anyone knew what could’ve caused it and why.

[paulstevenewing]

That’s really odd @Shivam_Shah
Makes me think there could have been two small holes in the cable from wear on the cable and sweat has gotten into the holes and started to react with the copper?

[Shivam_Shah]

Maybe but 2 holes pretty much one behind the other is a bit odd as if something pierced through it

[professor]

I am a heavy user of the Slim also, overall these are my most used BT devices. I am always wearing one round my neck, I own two and swap between then as they recharge. I do own the wireless Life P2 and the Neo but I like the wire to make the buds stay put round my neck when not in use and I can use one bud at a time and if they fall out the ear they just fall to my chest instead of to ground.

What I think has happened here is you kept that stupid plastic clip which pinches the wire. I ditched mine immediately. It is a stress concentrator which accelerates cable wear, the wire is pinched and bent and focuses wear. It probably slipped/moved during use and wore the holes. The holes then reacting with sweat, salt, oils and corroded the metal which then leached out dies and rust.

[Shivam_Shah]

Ok that makes sense and thanks for explanation. I used the clip because that made the earbuds less prone to swing especially on the controller side which made my right earbud fall off my ear. So yea I used to move the clip back and forth keeping decent sized loop (shown in photo) at the end when not in use

[professor]

No problem, stress concentration lesson-learned in engineering is about 90 years old.

Engineers know this, non-engineers just experience self-caused failure.

Back around 1940 it was a real problem, during WWII aircraft who were flying daily, if a bullet hole was made, would then form a crack which grew. What was figured out was you drilled a hole at the crack, would stop the crack growing, to give time to til you could do a proper repair.

Roll forward to 2020. That plastic thing is forcing the wire to bend. As you move, the strength of the metal on the inside of the bend is forcing molecular bonds on the outside of the bend to come undone, a crack is formed. Once a crack begins, the outside edge becomes a lever which then magnifies the stress into the crack so it accelerates. In 1940 you could pause that lever acceleration via drilling a hole.

There is inside Anker today an engineer who knew this 90 year old knowledge, and didn’t want the plastic thing, they got overruled by a non-engineer who wanted to adjust the cable length. You now witness the outcome.