A black screen on a computer monitor is a problem that users often encounter when using a computer. In fact, as long as you have a certain understanding of the motherboard, CPU, memory, display card and other major components in the computer hardware, the simple failure of non-component damage can be completely eliminated. In this case, you can follow the following repair steps and methods for analysis and simple maintenance: First, check whether the power supply of the main unit is working. Is the power supply fan rotating? Move to the air outlet of the switching power supply on the back of the main unit chassis by hand. If the wind blows out, the power supply is normal. If there is no wind, the power supply is faulty. When the main power switch is turned on, the three indicators (NumLock, CapsLock, and ScrollLock) of the keyboard are flashing. a bit? Yes, the power supply is normal; is the power indicator of the main panel and the hard disk indicator light? When it is on, the power is normal. Because the power supply is not normal or the motherboard is not powered, the monitor does not receive the data signal and obviously does not display. Second, check whether the monitor is powered on or not. Is the power switch of the monitor turned on? Is the monitor's power indicator light? Is the brightness potentiometer of the display turned off to a minimum? Is the high voltage circuit of the display normal? Move to the monitor screen by hand to see if there is “sound” and whether the sound on the back of the hand is erected. 3. Check if the contact between the display card and the monitor signal line is good. You can unplug the plug and check whether there is any bending or broken needle in the D-shaped socket. There is a lot of dirt, which is a problem that many users often encounter. When connecting the D-shaped socket, due to uneven force, or forgetting to tighten the socket fixing screw, the socket is not in good contact, or the D-shaped socket is broken or bent due to improper installation force, resulting in poor contact. 4. Open the chassis and check whether the display card is installed correctly. Is it in good contact with the motherboard slot? Is the display card or slot too dusty due to too long usage time, resulting in poor contact? Is there any burnt or cracking on the chip on the display card? When the display card causes a black screen, there will be a short and long “snapshot” when the computer is turned on. When installing the display card, hold the upper part of the display card with your hand and insert it evenly into the slot so that the fixing screw opening of the display card matches the screw opening of the main unit. Do not forcibly fix it when it is not inserted, so as to avoid distortion of the graphics card. If you confirm that the installation is correct, you can remove the display card and wipe the pins with an alcohol cotton ball or install it in a different slot. If it still doesn't work, try a good graphics card. 5. Check whether other boards (including sound card, decompression card, video capture card) are in good contact with the slot of the motherboard. Check whether the data cable and power cable connection of the hard disk are correct. Replace the slots of the other boards and clean the pins. This is often overlooked by many people. It is generally believed that the black screen of the computer is a problem in the display part, and has nothing to do with other devices. In fact, due to the incorrect installation of sound card and other equipment, the system initialization is difficult to complete, especially the data cable and power cable of the hard disk are inserted incorrectly, and it is easy to cause no display failure. 6. Check if the memory module is in good contact with the motherboard, and the quality of the memory module is too hard. Re-plug the memory module once, or replace it with a new one. If there is a problem with the memory module, the computer will have four consecutive sounds when it starts up. 7. Check if the contact between the CPU and the motherboard is good. Due to the moving or other factors, the CPU is in poor contact with the Slot 1 socket or the Socket 7 socket. Reinstall by manually pressing the CPU or removing the CPU. Since the CPU is a large heat-generating part of the host, the Socket 7 type may cause the motherboard to be bent and deformed, and the motherboard may be leveled on the bottom layer of the CPU socket. 8. Check the bus frequency, system frequency, and DIMM jumper of the motherboard. Check the jumper one by one. The sequence is “System Frequency Jumper —— CPU frequency jumper —— DIMM frequency jump Line & rdquo;, be careful when setting the CPU voltage jumper, should not be set too high. This step is very useful for some assembly machines or users who like overclocking. Nine, check the parameter settings Check whether the CMOS parameter settings are correct and the system software settings are correct. Check if the graphics card is compatible with the motherboard. It is best to check the information to set it up. X. Check whether the environmental factors are normal, whether the voltage is unstable, or the temperature is too high. In addition to checking according to the above steps, it can also be quickly located according to the working condition of the computer. For example, after the power of the host is turned on, the computer self-test can be heard. If the hard disk indicator flashes continuously, you should check it in steps 2 through 4. The above inspection method is based on the fact that the display itself has no electrical fault, that is, the power indicator of the display does not light after the power of the host is turned on. If the above steps are checked one by one and the display is still not displayed, it is likely to be a circuit failure and should be repaired by a professional.