Since the COVID-19 outbreak, I’ve decided to run through my list of personal projects and task that have fallen to the waist-side to higher priorities. One of those tasks was repairing my AIAIAI HM05s, the Bluetooth headband for my AIAIAI TMA-2 modular headphones. I searched around and was not able to find any teardown photos of this headband. This isn’t surprising to me because these headphones are not all that popular do to the company focusing on design over cost to performance. However, I thought the TMA-2s were a really neat idea when they came out, so I shelled out the money for it. I also paid a premium to make the TMA-2s Bluetooth enabled, when I joined the HM05 Kickstarter. Yes, my pair is the Kickstarter edition, which I do not know how it compares to the production version that is currently being sold, but I’m sure they fixed the issues that my pair started to develop over time.

I was very pleased with my pair of Kickstarter HM05s, with one major issue being the inital firmware. There were situations the device refused to go back into pairing mode, and the only way around it was to plug in a charger, which disables the device. The device cannot operate while charging, which is probably a quirk of the SoC that they are using. Other issues started to develop over time, which indicated issues developed due to wear.

  1. Opening the headphone over my head would kill power. Over time the distance that was required to disconnect power started to shorten, until the headphones would not power on or charge.

  2. The HM05 was no longer capable of clearing out paired devices or entering DFU mode. Testing this out further became impossible due to issue 1.

BAT- wire was disconnected. Noticed that BAT wires were quite tot adding stress to the solder point.

10K Ohm resistor on VOL- had been knocked off it’s pad.

Gross gunk everywhere. Wires everywhere. Solder on boards did not seem like they reflowed completely, but that’s the level of quality you get with a rushed Kickstarter campaign.