Solution:
The power supply current of the standard USB2.0 interface is 500mA, and the current provided by the MI box OTG function is up to 800mA, which can meet the power supply demand of most mobile hard disks. However, there are a large number of mobile hard disks in the current market with high power consumption, which is beyond the bearing range of Xiaomi box OTG. These mobile hard disks cannot be used, so please try to use them by connecting to auxiliary power.
Does it help?