What is the reason for the black screen when the computer is switched on?

1. When the monitor black screen does not have the image display (but the current market of the monitor in the host has no signal to send, the screen will monitor "No Signal line Connection"), first check the host power is plugged in good, the power supply fan rotation? Is the power LED and hard drive light on the host panel flashing? Because if the host power does not work or the motherboard does not power supply, the monitor does not receive the signal, of course, there will be no image display.

2. Check whether the power supply of the monitor is plugged in well? If the power switch on your monitor is a light touch switch, you should hear a slight "crack" sound when you give the monitor a tap, and then you can judge the switching power supply circuit of the monitor well. is the power switch on the monitor turned on? Is the power led on the monitor lit? when hand close to the monitor screen and slowly move whether there is a "hissing" sound, while the hands of the hair has been a feeling of suction, this check the display High-voltage circuit is working properly.

3. If it is determined that the display has been added, and there is high pressure, continue to check the data cable connectors and video card signal output interface is good contact? Is there any loosening? Then unplug the plug and check to see if there is a bent or broken needle or a lot of dirt in the D-type interface. This is a problem that many users often encounter, in connection with the D-type socket, force uneven, or forget to tighten the interface of the fixed screws, so that the interface loose contact is bad, or because the installation of improper or excessive force, so that the D-type interface has broken needles or bent needles, resulting in poor contact.

Note: The data cable plug of the monitor 15 pins may have missing needles, such as 4,9,11 needle, then normal, do not artificially use other wire to supplement these missing needle bit, lest cause other faults.

Say a little more: 1,2,3 needle for red, green, blue shots signal input, if which needle contact is not good, the screen will have a lack of corresponding color.

If the 12th, 15 pins have problems, the host will not be able to find the corresponding display, but this does not affect the use.

If the 13th, 14 pins have problems, the monitor will appear black screen, the monitor led in a few seconds after turning from green to orange. There is one of the above black screen.

4. Open the chassis to check that the monitor card is installed correctly? is the card or slot in good contact with the motherboard slot? is the video cards or slots due to too long time to accumulate dust too much, resulting in poor contact? Whether the chip on the video card has burnt or cracked marks. When the video card causes a black screen, the computer post is a short four-long "beep beep" sound. When installing the display card, it is necessary to hold the upper part of the display card by hand and insert the card slot evenly and forcibly, so that the fixed screw port of the video card matches the screw mouth of the main box. Do not force fixed when not inserted, resulting in distorted graphics. If you are sure that the installation is correct, you can remove the video card with an alcohol sponge swab the gold finger of the pin or switch to a slot (only for PCI video cards). If not, you can only change a good video card for a try.

If not, consider the compatibility of the graphics card with the motherboard when you are sure the video card is intact. It is best to check the relevant information or ask a netizen.

5. Check other board card (including sound card, decompression card, video capture card) and the motherboard slot contact is good? Note Check the hard drive data cable and hard drive power cord connection is correct? Replace other board slots and clean pins. This is a point that many people tend to overlook easily. It is generally believed that the computer black screen is a monitor and video card problem, with no other devices. In fact, because the sound card and other equipment installation is not correct, resulting in the system at the beginning of the difficult to complete, especially the hard drive of the data line and hard drive power cord plugged into error, easy to cause no display of the fault.

6. Check to see if the memory strips are in good contact with the motherboard? Reseat the memory strips once or in a different slot, or replace the new memory strips. If there is a problem with the memory bar, the computer will have a continuous "beep" sound when it starts. The beep is different because the motherboard is different.

7. Check CPU and motherboard CPU block contact is good? Due to moving or other factors, so that the CPU and SLOT1 socket or SOCKE370 socket bad contact. It is best to press the CPU by hand or remove the CPU and reinstall it again.

8. Check the CPU FSB, multiplier, memory frequency, such as jumper or CMOS settings are correct. Check the relevant jumper in the order of "CPU FSB jumper-CPU frequency jumper-memory frequency jumper" against the motherboard manual.

9. Check whether the voltage of the CPU is set properly. Be careful when setting up the CPU voltage jumper, be sure to match the working voltage of the CPU. These two steps should be checked carefully for some assemblers or for users who like to overclocking when a black screen appears.

10. Check that the CMOS parameter settings are correct. If your computer has two graphics cards, you set up the first PCI video card in CMOS, and your only monitor is connected to the AGP video card, and of course the monitor is not lit.

11. Check whether the working conditions required by the host and monitor are in line with the operating voltage is normal, the ambient temperature is not too high. In addition to the above steps to check, can also be based on the work of the computer to quickly locate, such as the power on the host, you can hear the "beep" to say that the computer self-test completed, if the hard drive lights flashing constantly, you should be in the second step to the fourth step check.

12. If the monitor in the computer startup process has content display, only after loading WIN98 screen appears black screen, this is just WIN98 system software aspects of the problem,

The above inspection method is based on the monitor itself without electrical failure, that is, the power supply led by the monitor is turned green to yellow, but there is no image display on the monitor black screen. If the display is still not displayed using the above steps, professional maintenance should be requested