It is useless for children to get in touch with health. It may be because of poor contact or broken. You can try this method:

1, open BBK Repair Master.

2. Select the standard mode and connect the computer and the mobile phone through the data cable.

3. Select the device type and enter DFU mode.

4. Download the firmware package, and then click Start Repair. After the maintenance is completed, use the touch key again to start the machine. If this method still doesn't work, it can only be sent to a repair shop for repair.