Analysis of several situations of computer booting black screen (1)

Analysis of several situations of computer booting black screen

The computer boot black screen, there is no display on the monitor after booting, it can be subdivided into the following situations:

1. The computer boot black screen, the performance of the power fan and CPU fan does not move, the indicator light on the motherboard does not light, the computer does not respond. At this time, first you should check if your power outlet is powered, whether the various power cables are good, and whether the connection is normal. If the confirmation is correct, please try again after replacing your power supply.

2. The computer turns on the black screen, the power supply fan rotates normally, the CPU fan does not move, and there is no alarm sound. The performance of the motherboard is not any reaction. At this time, you should first check whether the power supply socket of the power supply and the motherboard is tight. If it is checked, the motherboard may be seriously damaged or the connection between the power supply and the motherboard may be damaged. Try to replace the power supply to eliminate the second possibility; please check the motherboard abnormality, such as whether there is a capacitor bump (punctured), there is no obvious damage on the motherboard surface, the line is not connected, etc., you can get the repair station to check, there is If you can, you can change the motherboard to determine the next.

3. The computer turns on the black screen, the power supply fan and the CPU fan both rotate normally, but the display has no display and no alarm sound.

At this time, you should first be when the alarm sound is damaged, the display problem is eliminated, the connection between the monitor and the computer, the problem of the graphics card itself, or the socket card of the graphics card and the motherboard, and the mouse and keyboard are also checked. The connection (short circuit also produces a black screen) and the connection of each peripheral. So it is best to try it out with the minimum system method. If the fault persists after confirming the above error, please try the following method:

First understand the following knowledge: The computer startup process is a very complicated process, and it has a very complete hardware self-test mechanism. In the short few seconds of the power-on self-test, the computer has to complete more than 100 detection steps. First of all, let's first understand two concepts: the first one is BIOS (basic input and output system), the BIOS is a group of programs that are "cured" in the computer motherboard, directly dealing with the hardware, the computer startup process is on the motherboard Performed under the control of the BIOS. The second is the memory address, and the memory installed in the computer is given an address for each CPU.

When the power supply is initially powered, the voltage is still unstable. The motherboard control chipset will send a Reset signal to the CPU to initialize the CPU. When the power supply is stable, the chipset will remove the Reset signal, and the CPU immediately goes from the address FFFFOH. At the beginning of the execution of the instructions, this address is in the system BIOS address range, the general BIOS is here is a jumper instruction, jump to the real startup code in the system BIOS. The first thing to do in the system BIOS startup code is to perform POST (power-on self-test). The main task of POST is to detect whether some key devices in the system exist and can work normally, such as memory and graphics card. If the speaker of the system makes a harsh alarm at this time, it may be that the memory module or the display card has failed. The specific error can generally be judged from the length and number of alarm sounds. As for the specific sound, each sound represents What, since the relevant articles have been published many times, I will not elaborate here. Why is the error at this time to use the sound to alarm instead of displaying it on the screen? This is because the detection process of POST is before the initialization of the display card, that is to say, it is still "black screen" stage, so in the process of POST Some fatal errors were found that could not be displayed on the screen.

The next step will check the BIOS graphics card BIOS, call its initialization code after finding, recruited by the video card BIOS initialization complete graphics card. Most of the graphics cards in this process usually display some information about the display card on the screen, such as the manufacturer, graphics chip type, memory capacity, etc., which is the first screen we see when booting.

It is not difficult to summarize the following conclusions from the above text: the step of the computer booting to the display to display the first screen is: power supply to the motherboard — "the motherboard control chipset sends a Reset signal to the CPU & mdash;" CPU from At the address FFFFOH, execute the command — "jump to the BIOS boot code —" POST (power-on self-test) & mdash; "Check if the key device is normal & mdash;" display the video card information, and there is a problem in any part of the process, then There will be a black screen on the computer, so to solve the problem, just check each link. From the difficulty of inspection, we choose the reverse exclusion method to solve:

Check the key equipment steps, mainly to check whether the memory, graphics card and other equipment can work normally, here, you can first unplug the memory, boot Listen to whether there is an alarm sound, if there is, the previous steps are normal, the main problem is in the memory and the graphics card, you can use the replacement method to determine the problem, you can also use the alarm sound to determine the source of the fault. If the memory is unplugged, there is no alarm at startup. If the alarm sound is not ruled out, you can first determine the problem in the previous step.

BIOS boot code step: The code in the BIOS is stored in CMOS. The coms saves the configuration information of the bios, including the power-on self-test program, the bootloader program, the setup program, etc., which are powered by the motherboard battery. If there is a problem with the code in the CMOS (may be caused by a virus), obviously the boot cannot be successful. . So you have to re-flash the BIOS code (the method is introduced a lot on the Internet), the simple point is to take the motherboard battery, put it on for 5-10 minutes, discharge the CMOS to restore the CMOS to the factory settings.

CPU part: CPU is the control center of the whole computer, it has a problem, the computer boot black screen is affirmative. CPU problems are mainly concentrated in the following aspects: contact problems, CPU and motherboard contact is not good (have encountered before), resulting in the CPU can not work; heat problem, if the CPU fan is broken or the speed is very slow or the silica gel is dry, Will cause CPU overheating problem, and cause CPU burnout or overheat protection to cause the computer to boot black screen; CPU damage: CPU damage due to various reasons will obviously also cause the computer boot black screen problem, you can use the replacement method to determine whether the CPU is damaged.

Motherboard chip part: If the motherboard chip is damaged, the following steps can not be performed, the computer boot black screen is also inevitable, the chip damage is difficult to detect, generally get the repair station to check. If you have the conditions, you can replace the entire motherboard.

4. The computer turns on a black screen, the display shows a message, and it suddenly turns black when it is turned on. Most of this phenomenon is caused by viruses. See if you can enter safe mode (press F8). If you can, please check your startup project, start the service, start the driver, you can use this site “Windows Cleanup Assistant+sreng” The method to remove the virus, if not, then the system may have been destroyed, please restore or redo the system (hehe); it may also be caused by unstable power supply, replace the power supply check.