The black screen failure caused by the computer host fault can be mainly divided into the following categories:
1. The fault is caused by the power supply of the host
The black screen failure caused by the host power failure or the poor quality of the host power supply is very common. For example, when you add some new equipment, the display has a black screen fault, after eliminating the quality of accessories and compatibility problems, the quality of the power supply is not good enough power is the main cause of the fault, then you may also hear the speaker in the machine continuous alarm 12 sound, replace high power quality power supply is the best solution to this kind of fault. In addition, some motherboards have AT\/ATX dual power interfaces, and the wrong selection of jumpers can also cause such failures.
2. Fault caused by the quality of parts
Poor quality or damage of computer accessories is the main cause of black screen failure of the monitor. For example, the motherboard (and the motherboard BIOS), memory, graphics card and so on problems may certainly cause the emergence of black screen failure. Its fault performance such as the display light is orange, then replace the display card, memory, and even the motherboard, cpu try, is the fastest solution.
3. Quality of connection between accessories
The main cause of the black screen failure is the incorrect or loose connection between the memory graphics card and the motherboard. And the display card and the display connection problems may also cause this kind of failure, until the AT power plug is not correct or even if your hard disk or optical drive data line is reversed may also cause the start of the black screen failure.
4. Black screen fault caused by overclocking
Overclocking or overclocking of parts that are not suitable for overclocking will not only cause black screen failure, but also cause damage to parts in serious cases. There is also excessive overclocking or to the parts that are not suitable for overclocking after overclocking poor heat dissipation or heat dissipation fan damage in ordinary use, do not turn, and so on will cause the system self-protection black screen.
5. Black screen caused by other reasons
Other such as the motherboard CMOS setting is not correct and the motherboard clearing BIOS jumper is not correct can cause a black screen fault, then you can change its Settings according to the motherboard instructions. In addition, software conflicts such as improper installation of drivers, improper DIY such as BIOS refresh errors, incorrect power management Settings, hardware damage caused by malignant viruses (such as CIH), etc., may cause the occurrence of black screen failures. When you encounter this kind of failure, you may wish to think more carefully and consider the causes of the failure, so that you can solve the fault and know yourself and others.
Second, the black screen failure caused by the fault of the display itself
According to the author's usual experience, the black screen failure caused by the failure of the display itself is mainly caused by the following reasons:
1. The AC power supply is insufficient
Insufficient external power supply, resulting in some old displays or some displays with large power consumption can not start normally, is one of the reasons for the black screen failure caused by the failure of the display itself. Or the external power supply voltage is unstable, too high or too low may cause the display to not work.
2. The power switch circuit is damaged
The main cause of the black screen failure is the malfunction of the switch circuit of the display. Simple such as power switch damage or internal short circuit; Common such as switch tube damage or damage to its peripheral circuit components and so on.
3. Damage of line output circuit
The fault of the line output circuit or the kinescope and its power supply circuit is also the main cause of the black screen fault of the display. In particular, the damage of high pressure pack is more common in some miscellaneous displays that have been used for many years or have poor quality, resulting in no display black screen failure.
Third, the display black screen fault solution
For the display black screen fault how to repair, the following we will put forward some ideas for your reference.
First of all, for the computer host fault caused by the display black screen failure we can solve from the following ideas:
1. Check the installation quality of the parts
When you are assembling a computer or replacing accessories when a black screen failure occurs, you should first check the installation quality of your accessories. For example, whether the memory module is installed correctly or whether it is in good contact with the motherboard slot, whether the display card and other cards are installed in place, whether the relevant Settings in the BIOS and the jumper selection on the motherboard are correct, you can carefully refer to the relevant board manual for setting. In addition, it is also necessary to focus on checking the quality problems of the board itself and whether the relevant slots on the motherboard and the \"golden finger\" on the card have foreign bodies and are contaminated by dirt.
In addition, whether the CPU is overclocked or \"mistakenly\" overclocked (especially for some soft jumper motherboards, the system's \"automatic\" missettings are more likely to cause such failures), whether the hard disk or optical drive data line is connected, and so on need you to consider. And for such problems, it is best to give priority to the \"minimum system method\" and \"replacement method\" to diagnose, leaving only the motherboard, graphics card, memory, CPU to try, especially the quality of the memory caused by this kind of failure rate is relatively high, if no problem, you can focus on checking the quality of other accessories, such as still black screen, You can focus on these parts and then carefully install the connection and restart to try, if you can not solve the problem, the relevant parts can be replaced to try the quality of the accessories.
In addition, it is very important that you also need to understand the host power supply and power switch is good or bad and its connection is normal, they may cause the whole machine black screen, these you need to focus on understanding. If there is a problem with the power supply, then after you open the computer, you can see that the host case panel indicator is not bright, and you can not hear the rotating sound of the power fan in the host and the hard disk self-test sound, etc., which indicates that your host system does not get a normal power supply. This kind of problem you should first check whether there is an alternating current coming from the outside, and use the measuring pen to see if there is electricity on the power socket. Next you can measure whether the power line is connected to the side of the host power supply, if necessary, use a multimeter to test whether its voltage is enough, the voltage is too high or too low may cause the host power supply overvoltage or undervoltage circuit automatic shutdown protection, if the above is no problem, then you should first focus on the maintenance of the host internal and power switch and reset key, Also using the minimum system method and replacement method, one by one to remove the host plug-in card and other equipment power lines, signal lines, and then power on the test machine, such as when the host power supply recovers when removing a device, it is just removed equipment damage or improper installation caused by short circuit, so that the short circuit protection circuit in the power supply starts, stop the power supply to the equipment in the machine, then you can focus on its contact check, Replace and try again if necessary; In addition, it is important to check the quality of the power switch and the reset key and whether they are correctly connected to the motherboard, because many of the power switch and the reset key on the inferior chassis often occur after the use of several times the internal metal contact sheet breaks and the power short circuit occurs, resulting in a black screen without any display. If the above checks do not solve the problem, then please replace the power supply.
2. Listening to the fault of color discrimination
For example, the host normal self-test, but the display appears \"black screen\" fault, for this fault we can focus on the motherboard - display card - display cable - display this idea to consider. First of all, check whether the display power indicator light is on, such as normal, you can focus on adjusting the brightness, contrast button, to eliminate the \"common\" such false black screen fault. If there is no problem, then you can focus on checking whether there is a problem with the connection cable of the host display card to the display and whether the pointer in the plug on the cable is crooked and broken and whether it is closely connected to the display card, in addition, you can remove this cable connector to see whether the display can be normally lit up or connect the display to other hosts to try. It is used to determine whether the fault is caused by the host or the display itself.
For example, the display black screen and the host horn issued a long, two or three short beep or continuous beep, indicating that the connection between the display card and the motherboard has a problem or the connection between the display card and the display has a problem, you can focus on checking whether the slot contact is good, whether there is a foreign body in the slot and can replace the video card to try, if no improvement, can initially show that the problem is on the motherboard, Try the graphics card on another motherboard. For example, the appearance of a continuous long sound, most of it indicates that there is a problem with the memory, you can focus on checking the installation of the memory and memory slot contact. If the machine emits a continuous short sound, it indicates that there is a slight short circuit phenomenon in the machine, and the minimum system method and elimination method can be used to solve the problem until the short circuit is found. In addition, if you hear two short beeps, it indicates that there may be a problem with the motherboard or the display card or the display, if the display is not connected, if it is still so beeped, there is a problem with the display card, if it becomes a short sound, it indicates that there is a problem with the display end.
For the black screen failure caused by the display itself, we mainly provide you with more specific maintenance ideas from the following points
1. Quick repair of black screen of monitor
If there is no display after the display is turned on, after excluding the cause of the host, you can first check whether the display protection circuit is working because the voltage is too high or too low, and check whether the acceleration pole voltage is normal. In addition, it is important to check the following problem-prone parts, such as to see whether the fuse is blown, whether the rectifier bridge switch tube is broken, whether the current limiting protection resistance is burned, etc., these parts can sometimes be seen from the appearance of its burned black and other fault phenomena. Then focus on checking the line output tube, transformer, low-frequency rectifier, high-frequency rectifier and other key parts of whether there is damage or performance degradation or virtual welding, the general display black screen failure you can quickly get rid of the disease as long as you start.
2. Fault diagnosis of line scan circuit
The fault of line scan circuit is an important reason for the display without raster and screen after power on. For this kind of failure, the maintenance can focus on the line scan circuit, can first check whether there is a problem with the line oscillation circuit, in addition to checking whether the peripheral components of the line oscillation chip are damaged under amateur conditions, you can also replace the line oscillation chip to try, in addition, the line push tube is damaged or its working status is abnormal, the line output tube is damaged or the line output load is faulty may cause the above faults. At this point you can try to repair and replace the parts. If there is a problem with the output circuit, it is generally restored to normal after this overhaul and replacement.
3. Fault judgment of kinescope and its power supply circuit
Abnormal kinescope and its power supply circuit can also cause the failure of the display without raster black screen. At this time, we can first check whether the kinescope filament is bright, and use a table to measure its filament power supply circuit to see whether its filament voltage is normal. In addition, if it is found that the filament electric block needs to be replaced with a good filament limiting resistor, if it is found that the picture tube filament is broken, it is necessary to replace the picture tube. If the above is normal, we can focus on checking whether the acceleration pole voltage of the picture tube is normal, especially if the acceleration pole voltage connection is broken, which is the main cause of such failures, and it can be replaced. If there is high voltage, we can focus on replacing the line output transformer (high voltage pack), the damage of this part is one of the main causes of the black screen failure of the display. In addition, at the same time of the above maintenance, we can also check whether the cathode voltage and the view-discharge voltage are normal, if the view-discharge voltage is not added or its voltage is not normal, it is also one of the important reasons for the display power without grating and black screen