At precisely 9:20 PM, Zhao Xin commences his Douyin live - streaming session without fail. The day before, a follower had mentioned an odd noise emanating from their robotic dog's knee joint. During the live stream, Zhao Xin intended to take apart the knee - joint motor of the robotic dog. This would serve a dual purpose: acting as a tutorial and providing a remote diagnosis. He offered a concise summary: A "rustling" noise typically signals the need for lubrication. A "clicking" sound might imply an issue with the gears in the planetary gearbox. And a "buzzing" sound could well indicate a short - circuit on the circuit board.