Sony WF-C710N FCC Teardown
The FCC internal photos of the WF-C710N have become available. So let us see what secrets the new model is hiding and how the design compares to the WF-C700N. While this not a step by step teardown like 52Audio’s. we are able to see all of the major components and parts inside.
Check out the announcement post for more details on the headset.
This first photo does not really show much, to be honest, but I suspect we have clips and tabs holding the case together, like in the old model. The case battery, as with all of Sony’s earbuds, is underneath the plastic piece which the PCB sits on. While it is difficult to tell from these photos, I feel there is space for a wireless charging coil. Considering the new LinkBuds Fit did not receive wireless charging, it makes sense why the WF-C710N did not either. The battery/PCB assembly is screwed into the underside of the middle piece (top left corner).
The case PCB size has decreased in size when compared to the WF-C700N. We now have two ICs, one on each side, and 2 charging pins per earbud, 5V and ground. Unfortunately the photos are not clear enough to make out the writing on the chips. Sony still uses the old HDX-#### model names on the PCB, rather the YY code designations.
The board also has a date code, 2434, meaning 2024, week 34, or the second last week of August in 2024. Not sure if this is just for the certification prototype, or if Sony (actually Cresyn) started production around the same time for the retail units.
A major change is the addition of a battery connector on the board, where previously the battery was soldered directly to the board. There are now 3 cables connected to the battery, just like the new WF-C510, and Sony’s other newer earbuds. From what I have read online, the third wire is for the thermistor, which monitors the battery’s temperature when charging.
Neither the WF-C500 nor WF-C700N had this extra third wire, so I am unsure if the case batteries had any temperature monitoring. I am sure there is charge protection on the case batteries but perhaps not related to temperature, just current? This could explain the recharging issues users have experienced when recharging with AC adapters. Sony recommends only AC adapters with less than 13W when recharging.
Removing the top of the earbuds, we can see the touch sensor and wireless antenna on the underside. The top of the main PCB is visible here with 2 pin connectors for the touch sensor and antenna. The wind reduction structure is visible just under the touch sensor, and seems identical to the one seen in the WF-C700N. The previous model used a physical button (see photo below), but the general design is similar between the 2 models.
Removing the PCB and battery, we can see there is a foam spacer (1) between the battery and the flex cable assembly. The voice/feedforward NC microphone is also visible in this photo (2).
The flex cable assembly connects to the PCB with a connector.
