First of all, there should be a setting in the power management item of the phone, there should be a \"do not charge when connected to the computer\
2 The option to turn off usb charging mode is hidden, use the next function key →*←←*←* Right-asterisk-left-left-asterisk-left-asterisk-This will open a menu, which has a service setting, and then change to charge off so that the charge off is for you to connect usb does not charge.
3 Generally speaking, the USB charging function of the mobile phone can not be turned off, because it is to ensure that there is sufficient power when transmitting data, to prevent data loss due to too low power.
4 The USB port voltage is insufficient. When the mobile hard drive is connected to the front USB port, there is a possibility that the system cannot recognize the fault of the device. The reason is that the mobile hard disk power is relatively large and the voltage is relatively strict, and the front interface may not be able to provide enough voltage, of course, poor quality power supply may also cause this problem