Win10 mobile hard disk is not ready? Problems with USB!

Yesterday, a small partner left a message, his computer access to mobile hard disk error can not be used, suggesting that the device is not ready, but it is good to install on other computers, help Xiaobian. In fact, this is not a problem with Win10 or other operating systems. The problem lies with the USB interface.

The so-called “device is not ready” by the computer indicates that the reason is particularly simple—the USB power supply is insufficient. Just in Win10 before the computer, the prompt is not this, nothing in the case of Win10 USB power supply is the tip.

Xiao Bian specifically said that in the USB 2.0 specification requires the device power supply capacity of 5A can supply 0.5A current, and to the USB 3.0 specification, to 1V of the supply current to 5V voltage; to the latest USB 3.1 standard, The following jumped to a power supply that can reach 5A at 20V.

Generally speaking, the power requirement of the mobile hard disk is 500ma, that is, the 0.5A level. It stands to reason that even a USB 2.0 interface should be enough, but this is not necessarily the case - there are several situations that will lead to the situation that the device is not ready. :

The first type is the lack of power supply to the device interface. This is related to the design of the motherboard. Some USB ports on the motherboard are naturally underpowered and cannot reach the power supply level of 500ma (not to mention, many USB 2.0 ports on the motherboard supply less than 500ma). So at that time, many mobile hard drives were designed with dual USB cables; now that USB 3.0 interface computers are popular, this problem is rarely seen (USB 3.0 power supply capacity is 5V 1A).

The second is the use of USB-HUB. It should be said that most USB-HUBs do not have a standard power supply. This means that these "extended" USB ports are all powered by the shared port. The original form. The keyboard, mouse, and even USB flash drive are all OK on USB-HUB, mainly because their demand for power supply is very small.

The third type of USB cable is poor in quality or long, and the power supply is attenuated. This situation also leads to insufficient USB power supply. In general, the USB cable is preferably not more than 30 cm, otherwise it is difficult to ensure adequate power supply.

In the first case, if all USB 2.0 ports on the motherboard (computers without USB 3.0) have this problem, the easiest solution is to purchase a USB-HUB with a power connector and provide it with a separate power supply ( Recommended 5V 2A charger) This also applies to the second case. As for the third category, Xiaobian strongly recommends that you use the original wire of the mobile hard disk. If it is a special need to have a long cable, it must not exceed 30cm in length, so that the situation of insufficient power supply can be avoided as much as possible. The other is to use USB 3.0 interface, do not think there is no power supply problem, some special specifications of mobile hard drives, such as 15cm thick large-capacity mobile hard drive, its power supply requirements may reach 700ma, some lack of power supply virtual USB 3.0 interface The same situation of power shortage will occur.