After the computer is cleaned, the black screen is turned on, and there is no self test sound

Black screen at boot. Phenomenon: The black screen is turned on and there is no display, and there may be an alarm sound.

Phenomenon analysis: Poor contact between hardware, or hardware failure, related hardware involves memory, graphics card, CPU, motherboard, power supply, etc. The boot of the computer must first be powered by the power supply, then guided by the motherboard's BIOS self-test, and then through the CPU, memory, graphics card, etc.

This process is reflected on the screen called self-test, first through the graphics card BIOS information, then the motherboard information, then the memory, hard disk, optical drive, etc. If something goes wrong with any of these steps, the computer won't boot up properly, or even go black.

What to do: First, make sure that the external and internal connections are connected smoothly. The external connection has a monitor, a host power supply, etc.

There is a cable between the host power supply and the host power connector inside (sometimes the contact here is not good). The more common reasons are: graphics card, memory due to long use, long-term contact with dust in the air, resulting in the oxide layer on the gold finger, resulting in poor contact.

In this regard, rub the gold finger back and forth with a moderate amount of alcohol glued to cotton, and insert it back after drying. In addition, observe whether the CPU is working normally, turn on for about half a minute, and touch the heat sink of the CPU fan with your hand to see if there is a temperature. If there is a temperature, the possibility of CPU failure can be basically ruled out.

If there is no temperature, tidy up the socket of the CPU to make sure the contact is in place. After that, before the temperature, your CPU can be upgraded: (In addition to the above method, there is also a special move:

Clear the BIOS settings by unplugging the jumper or replace the CMOS battery of the motherboard. When all of these methods have been tried and failed, you can summon Big Prawn to come out of the mountain to help.

Try reinserting the memory, and make sure the graphics card is plugged in tightly.

It's possible that your memory card is loose. You can reinsert the memory card from scratch.

A black screen is a common phenomenon, especially on older computers or builds. There are many reasons for the failure of a computer black screen, such as a damaged monitor, a damaged motherboard, a damaged graphics card, a poor contact of the graphics card, a damaged power supply, a damaged CPU, etc.

1) The monitor is powered off, or the monitor data cable is in poor contact. In addition, the computer has been used for a long time, and the power cord of the monitor is easy to oxidize and break;

2) There is no power supply to the motherboard;

3) Poor contact or damage to the graphics card;

4) Poor CPU contact;

5) Poor contact of memory modules;

6) The machine is infected with CIH virus, and the BIOS is refreshed destructively;

7) Check the plugging and unplugging, if necessary, you can use a rubber to remove the oxide film on the gold finger;

8) If the floppy drive has a floppy disk, many times it will cause the computer to start or restart, and the computer will have a black screen and cannot enter the system. To avoid such situations, it is also possible to cancel the floppy disk boot item in the BIOS.

For the treatment of the black screen of the computer, the method of eliminating and replacing is basically adopted, and the principle should be based on replacing and eliminating the most suspicious parts first. For ordinary computer users, professional knowledge is insufficient, you can follow the following steps to analyze the cause of the failure, so that you can do it yourself.

Start by checking that the contact is good. Check whether the contact between the graphics card and the monitor is good, and whether the contact between the graphics card and the motherboard IO slot is good, and if necessary, remove it and reinstall it again to ensure that it is installed in place and in good contact.

If there is no problem with contact, it is best to try a different monitor to make sure that the monitor is fine.

If there is no problem with the monitor, check whether the CPU fan is running, if it is running, use a multimeter to measure whether the voltage output is normal to 12V, 15V, if not, you can change the power supply to give it a try.

If the black screen still appears, take out the components installed in the computer, leaving only the CPU, graphics card, and memory sticks, and the cause of the fault can be limited to the CPU, motherboard, and memory. Generally, if there is a fault in the memory, there should be an alarm sound. If the memory fault is ruled out, only the CPU and the motherboard are left.

Change to a normal CPU (should be compatible with the tested computer), boot the computer and re-test, if the black screen still appears, you can only change to a motherboard, and the problem should also appear on the motherboard.

A black screen may indicate a serious problem with your computer, and you may wish to eliminate it as described above when the black screen occurs. In the process of treatment, the method of exclusion and substitution should be flexibly applied, and the phenomenon that occurs in a timely manner should be excluded.

I guess it's a problem with the graphics card! You can first remove the PC's graphics card and see if there is still a sound, if there is no sound, the graphics card is loose or burned!!

It is also possible that the memory is loose.

It's very stuck, and the screen is black.

It could be a problem with the graphics card driver... How many megabytes of graphics card are you.