What should I do if the USB interface power supply is insufficient?

The failure caused by insufficient USB power supply is becoming more and more obvious now, because our equipment is improving or our power supply and other equipment are aging. What we can do for this phenomenon is not to replace the equipment, or to increase the current or voltage of the power supply by other means to continue to use. 1. When the USB interface on the motherboard has a jumper that can change the power supply mode and the mobile hard disk can't be used normally, we can try to change the power supply mode and change the original auxiliary power supply+++5VSB power supply to the main power supply +5V power supply to see if the mobile hard disk can be used normally. One thing: The switching power supply of ATX V2. 1 version we usually use can only provide++5Sb1.5A current. But in fact, in order to reduce the production cost, most manufacturers of switching power supply use low-frequency transformers to directly reduce the voltage of+++5VSB power supply, and provide it to the host after being stabilized by 7805 regulator. Some use single-tube self-excited switching power supply circuit, and independent 3-5W switching transformer provides DC voltage of ++ 12V, which is then stabilized by 7805 and provided to the host. The main function of auxiliary power supply in the host is to provide functions such as starting circuit, network wake-up, M wake-up, keyboard start-up, etc. Generally, this part of the circuit needs less current for the auxiliary power supply, so most hosts will not have any problems when using this power supply. Because the 7805 can output current of 1.5A with standard heat sink, and most manufacturers do not use heat sink or use small heat sink in production, its radio wave output is only 500MA at most, especially when it works for a long time with high current, the output current will decrease with the increase of working temperature and will stop when it reaches the cut-off temperature. Therefore, when the USB interface of our motherboard is powered by ++5VSB, there will definitely be problems with the mobile hard disk. For the host that can only use auxiliary power supply, if this problem occurs, you can try to replace the high-power brand switching power supply to solve the problem. 2. For motherboards with strictly limited power supply current, in order to ensure the normal performance of motherboards, motherboard manufacturers use electronic circuits to ensure that the current output of each USB interface is 500MA. Therefore, when the mobile hard disk can't be used, we can only replace the 2.5 "hard disk with large capacity and low power consumption, or use the mobile device with external power supply to ensure its normal use. 3. The power supply of the two USB interfaces under the keyboard and mouse is assisted by other USB interfaces or PS/2 interfaces. The power supply is the same as the keyboard and mouse, and most motherboards on PCB are directly connected together. So when the mobile hard disk can't be used, even if we plug in the PS/2 interface, the increase of current will not change much, and the mobile hard disk can't be used most of the time. At the same time, it is possible to burn the interface and control chip when plugging and unplugging PS/2 interface with electricity, which needs special attention. In general, the power supply of mobile hard disk with USB interface is directly taken from +5V of USB interface. Note that some mobile hard disks have two parallel USB interfaces, but the one on the side is not a data interface, but is set to assist in providing large current when the power supply of the main USB data interface is insufficient to ensure the normal operation of the mobile hard disk. But in fact, the power supply of two rear USB interfaces or two front USB interfaces on the motherboard comes from the same path, that is to say, whether one or two USB devices are used, the total power supply current is limited in a certain range, especially for the power supply with poor host performance or low power. Therefore, when we use the high-speed mobile hard disk with a capacity of more than 40G, the power supply is often insufficient and cannot be used normally. At this point, even if we connect two USB ports, we can't meet the power supply requirements of the hard disk and still can't use it. However, this situation can be used for four or six front USB interfaces or more than four rear USB interfaces, because usually the power supply of USB interfaces is that one USB host hub supports two USB interfaces, sharing a set of power supply, and different USB interfaces use different power supplies. Be careful not to connect to a set of USB interfaces. 4. Directly use external power supply For the 3.5 "mobile hard disk, due to its large working current, mobile hard disk box, which supports this kind of hard disk, uses external power supply to provide additional power of ++ 12V and +5v, so there is basically no case that" the mobile hard disk can be found but my computer does not display the drive letter "due to insufficient current power supply. For the 2.5 "mobile hard disk over 40G, due to the increasing working current, the +5V power supply of some high-speed hard disks has reached 1A, and the normal operation of hard disks cannot be satisfied only by USB interface. Most of them are as follows: the mobile hard disk can work normally on some machines, but only the mobile hard disk can be found on some machines, and the drive letter is not displayed; Some will sometimes be able to read the disk on some machines, and sometimes they can't; It can work normally when copying small files, but when copying large files such as movies and music, there will be data loss and drive letter loss. Therefore, it is suggested that the large-capacity 2.5 "mobile hard disk should also be equipped with an external power supply to ensure the stable operation of the mobile hard disk. Other hot topics about USB devices: What should I do if the power supply of USB interface is insufficient? Why does USB hard disk not recognize, but U disk can recognize? The motherboard of MSI G4 1M-S26 has USB problem. The external USB keyboard is unstable. What should I do?