bought a yi dashcam from Kopipeng, delivery was fast (received on 11/07/17; a day after payment). 1st day in testing (12/07/17) and found that video have no sound. tried reset (poking the side button) and the reset in the camera menu. reformatted the SD card. all did not work. lastly i tried shouting over the microphone hole directly and played the video via desktop with my speakers volume cranked up to the MAX. the sound was played softer than in real life. i told the seller about it but his reply was "its a common issue. hope they will fixed in future firmware update". any advice?