Monitor the black screen, troubleshoot, check the main power supply, and work normally. First, the power indicator light on the main box panel lights up, and the power supply of the host system is driven by the rotation of the Yao Ming and the power supply fan. Secondly, check whether the external voltage of the multimeter meets the requirements. If the voltage is too high or too low, the main power supply may stop automatically under overvoltage or undervoltage. In addition, it is also very important to check whether the power switch and reset key of the motherboard are connected correctly. Black fault caused by computer hardware fault and computer hardware fault can be divided into the following two categories: black 1 when the host or host power supply is turned off, black caused by power quality loss fault and black caused by host system fault. For example, if some new devices are added, the display will have a black screen failure. Poor power quality and poor hardware compatibility are the main reasons for the power failure, or the best way to solve this failure is to use a power supply with replacement rate. The main reasons are parts quality failure, computer parts quality damage or black screen and black screen failure. If the interface has a lot of dust, broken needles and other damage will lead to poor contact and black screen. D Is check card in good contact with the motherboard? If there is an accident between the display screen displayed by the speaker and the host, or if there is a problem in the connection between the graphics card and the motherboard, or if there is a problem in the connection between the graphics card and the monitor, you can check whether the key slot is a well-contacted pool or a foreign body, which is used to show the card test board slot and determine the slot problem. Whether check card is working normally. Check whether the chip on the graphics card is burnt out and cracked, whether the cooling fan on the graphics card works and whether the cooling performance is good. Replace the normal graphics card to eliminate the damage of the graphics card. Check that the memory is in good contact with the motherboard and the memory quality is good. If the computer starts to go blank and the host beeps continuously, most memory problems can be checked by installing contacts, key memory and memory slots, replacing memory or replacing memory. Check whether the fan in the box is turning. If the cooling fan is damaged, it will lead to poor cooling, damage to CPU and other components, or automatic shutdown alarm. Check other motherboards (such as sound card, decompression card, video card, acquisition card) and motherboard slots, and connect signal lines. This is often overlooked by many people. Generally speaking, the computer black screen is a part of the monitor, and this problem has nothing to do with other devices. In fact, the sound card and other equipment are not installed correctly, which makes the system initialization difficult to complete, especially the hard disk data line interface, and it is also easy to cause fault display.