Ebay or Aliexpress would be my first stops. It’s not a particularly new phone, so stock might be harder to come by

Glad to hear! And considering how many views this manual continues to get, I'd say a lot of people would find it a helpful guide.

Feel free to recommend changes where you found a better technique.

But keep in mind, everyone starts from a different position. I personally take the approach to overestimate work rather than underestimate, I've also rarely found that belittling people or their progress is helpful in the end. I'm not claiming to be one, but the sign of a true master is the ability to appear humble and let their work speak for itself.

If you ended up taking pictures or a video of the process, I can definitely add this to the guide.

I could be wrong, but it seems to be on the right side of the phone somewhere (power button side). I don't have the phone anymore to confirm. Look for a small hole in the side of the case. If it's not there, it would likely be on the top.

If I were you, I'd try measuring your battery's voltage with a multimeter. You can use sewing needles to get inside the contacts for the battery, and touch the sewing needles to the multimeter leads.

If the voltage is extremely low, the battery charging circuit might think there's a malfunction and just "refuse to try". Without fancy equipment, I'd recommend buying a new battery (see the model # and ebay for some hints).

If the battery is around 2.8-3v, the battery is dead, but "reasonably dead", and it likely means your headphones have a faulty charging circuit. You can try inspecting the components on the board shown here and see if any look "burned", smell weird etc., but if nothing looks suspect I'd just try to buy that circuit board again if you can find one (ebay is probably your only good source here... or someone else who's visiting that has a faulty set).

If the battery has a high voltage (like around 3.5v+)... well, you're in the same boat as I was, and it's not a battery or charging issue -_-

Thermal paste doesn't really have a place around wires, but it's messy and could have just been spread around at the factory by accident. This shouldn't make or break anything for you.

The third option would seem kind of flexible/rubbery, this I believe is essentially a silicone compound not too different than what you use around a bathtub. It's used in the same sort of ways hot glue is, but has a very useful property - silicone doesn't melt under high heat. So you can isolate connectors, provide strength etc., and not have to worry about hot components reflowing your adhesive.

Hi Rico, I don't have the headphones anymore so I can only provide speculation. Long story short - it likely isn't the source of a problem, or a solution to your charging problem.

In one of the pictures here you can see some industrial "glue gun" glue (same idea anyways), that is used to isolate the wires in case one comes loose (so they don't short each other out), and also to provide stress relief - any tugging on that wire will be distributed more evenly than if it wasn't there.

If the substance you're talking about is actually white, it's usually one of 3 things - first, could be corrosion of some sort. Check if the substance feels powdery/chalky - if so, this could actually be a problem area. I have my doubts that it would form by the wires though... but thought I'd throw it in anyways. Second option - if it's more of a "paste" (still somewhat fluid), it might be thermal paste, used to transfer heat to another component.

The charger assembly was in working condition, and the device signified that it had external power plugged in. I did not check if there was current going through the charging circuit, because the battery was already above nominal voltage and therefore fully charged (as a battery charger would read it).

I'm not sure what you mean by user-friendly... the headphones were well taken care of until the very end of the disassembly, if you are referring to product care. If you mean that the guide is not user-friendly, please make your own concentrating on the parts that you feel were missed. It doesn't sound like you are qualified to be editing this one.

To anyone who reads this looking for more information on diagnosis, I would begin looking at the surface-mount capacitors if you suffer from the same issue as I did. They are a weak point in many electronics, and do not fail immediately (potentially causing the slow shutdown). Unfortunately at the time of writing, no such resource exists for capacitor values.

I believe your first point is incorrect in most (if not all) situations - a battery can usually provide far more amperage than the device that it powers. As it dies, it is unable to produce the required amperage at the specified voltage - and by some physics principle that I am not well enough informed on, it is able to meet the amperage by decreasing the voltage. The voltage continues to decrease until it is no longer sufficient to power the components in the device. In essence, the mAh rating would drop, but only because this is still a fancy way of measuring wattage over time (with a cutoff for when voltage is no longer acceptable).

I have contacted the company for any possible reset instructions, none of which worked. I even tried many of the "home therapy" techniques listed here and elsewhere, to no avail. The device did reset, but constantly needed more resets, as expressed in the guide.