1. First, click the "Dial" icon on the desktop, enter the dialing interface, and enter "

? * # * # 2846579 # * # ",as shown in the figure below, and then go to the next step.

2. Secondly, after completion, it will enter the factory mode, as shown in the figure below, and then enter the next step.

3. Next, you can set the background in the project menu, as shown in the figure below, and then go to the next step.

4. Then, you can also query the single board information, as shown in the figure below, and then go to the next step.

5. Then, you can directly restore the factory settings, as shown in the figure below, and then proceed to the next step.

6. Finally, exit the factory settings. You can successfully exit by clicking the arrow in the upper left corner, as shown in the figure below. In this way, the problem is solved.