Note: The working voltage of this product is 5V, and it is forbidden to use a voltage higher than 5V to power the product. Frequently Asked Questions: 1. No display on the screen, no powerPlease check whether the USB cable is damaged, or replace the USB cable for testing(Attention: It is forbidden to use a voltage higher than 5V)2. No speed displayAfter powering on, the satellite icon flashes to indicate that it is in the state of satellite search, please move the car to the open road to receive the signal, and the machine can be used normally after the satellite icon stops flashing and displays the number of satellites3. The speed is still displayed after the car stopsIf driving to underground parking lots, tunnels, under flyovers, or other places that make the signal unstable, the data displayed by the product may have a certain deviation, and the car can return to normal by driving to an open road4. The speed is not accuratea. Check whether the unit is correct, Km/H or MPH (please refer to the setting mode in the figure above for speed unit switching)b. The vehicle speed can be fine-tuned, such as the dashboard displays 100Km/H, the machine displays 105Km/H, and the parameter value can be adjusted to 1025. Time calibrationa. The default of the machine is +8:00