Broken Tempest Hub Teardown

After a few months, the tempest hub started to get increasingly unreliable and has eventually failed, by simply not being able to connect to the wifi network or bluetooth after a reset. When contacted, weatherflow support was super helpful and just sent me a new hub, so thumbs up for that.
However, I was curious to find out why the hub failed, so I took it apart. The screws are hidden under the rubber feet, but sadly, the whole bottom is additionally held in with plastic clips. Opening the case requires a bit of prying, leaving some marks at the seam.

On the top, there’s the proprietary 868 MHz / 915 MHz wireless module with a Silicon Labs EFR32FG1P131 Sub-GHz wireless SoC:
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And on the bottom right, we have the Avnet AES-BCM4343W-M1-G WLAN and BLE Module with some nice fractal antennas. The main chip SSB-WBM-N08 is actually a System-in-Package by Siliconware Precision Industries, and contains a Cypress BCM4343W WLAN and Bluetooth SoC, and an ST STM32F411 ARM Cortex M4 microcontroller.
[Image in next post.]
Something in that SiP has definitely gone horribly wrong and it is getting very hot. After removing the sticker, I’ve tried putting a heatsink on it, hoping it just doesn’t work due to an oscillator getting too hot and drifting out of tolerance, but no luck, this is gone for good. I guess the whole reason why it failed in the first place is the SiP running too hot during nominal operation, as evident by the browned plastic mounting plate behind the PCB, so equipping it with a heatsink from the factory should definitely lower failure rates.


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