What if the computer can't be plugged in and turned on?

1. The computer won't open, and there is no response when the switch is plugged in. What happened?

Press the switch to see if the CPU fan rotates. Can the CD-ROM drive still be turned on? If everything is normal, the power supply is good. If not, it may be that the power supply is broken, but there is something wrong with the motherboard power supply.

The abnormal sound at startup may be the hard disk. It's not easy to find the reason for the parts that haven't been changed. Go to the computer city and have them repaired.

Just two more questions. We don't need this commodity. If you can't find the reason, say that the motherboard "bridge" burned. We need to replace the motherboard. If it is a motherboard problem, of course we can replace the motherboard. But their so-called "new" motherboards are all made in small factories, and the quality is not guaranteed, because the slightly older motherboard manufacturers have stopped production, unless they happen to have the old motherboards you need and can repair them themselves best. "Bridge" is not so easy to burn. Motherboard can't be repaired except "bridge" (many pins and precise), and it is not necessarily worth repairing. There is also a memory slot that is slightly troublesome, and everything else can be repaired.

Generally, a small problem, 30 yuan, is to change a diode or a diode. Last year, I bought a Seagate 80g second-hand hard disk, 130 yuan, and now I don't need 100 yuan. Last year, I bought a 30-yuan second-hand power supply, and the second-hand accessories are generally tens of dollars, which are very cheap. Since the financial crisis, I went to the computer city this year and found that the prices of old and new computer accessories have dropped significantly. Most of these are last year's prices, and now the prices should be cheaper. I heard that some old motherboards can be bought in their twenties and thirties, but they are neither old nor cruel.

The computer can't be turned on when it is plugged in.

The reason why the computer can't be turned on and the solution;

Step 1: If there is no power supply response, check whether there are problems such as power supply, poor contact and hardware, and proceed to step 2. If you can't access the system, it may be an operating system or software problem. Go to step 3.

Step 2: Check whether the power supply is faulty. First, check whether the power supply is not plugged in or the plug is faulty. If the battery is used up, please plug it in and try again. You can try to find a friend or go to a computer repair shop or a sales store to find the same type of power supply. After plugging in the power again, press the power button again. If it still won't open, press it for a while. If someone else's power supply can be connected, it means there is something wrong with the power supply. If it proves that there is nothing wrong with the power supply, it may be a hardware problem. Go to step 5.

Step 3: Enter the last correct configuration to adjust, press F8 to enter the advanced options page, select "Last correct configuration" and press enter. If you can get into the system, it may be caused by virus infection, incompatibility between hardware drivers and the system, operating system and other reasons. After entering the system, run anti-virus software to kill virus. If there is a virus, restart the computer after antivirus. If it is not normal, it may be caused by incompatibility between the device driver and the program. Delete drivers such as graphics cards and network cards, and restart after deleting the drivers. If there are still problems, then proceed to the next step.

Step 4: Repair the installation or reinstall the system, set "CD-ROM as the first boot device" in the BIOS, then insert the system disk and press R key to "Repair the installation". If the fault remains, at the beginning of entering the system, select "one-click gost recovery system" or reinstall the system with the system disk.

Step 5: Check whether there is any hardware problem. Disassemble the notebook and check whether the hardware is loose. In general, if the hardware is not plugged in properly, there will be an alarm. A long tone means that the memory stick is not inserted tightly, a long one means that there is a problem with the memory or motherboard, and a long one means that there is a problem with the graphics card. If there is too much dust in the notebook, you'd better clean it first. Also pay attention to whether it is caused by new hardware. If the hardware is normal before replacement, it will be abnormal after replacement, and then check whether it is compatible. If it can't be started at this time, it's best to send it for repair, and professionals will check whether there is anything wrong with the hardware one by one.

Plug something into the USB socket and the computer won't turn on.

Is yours a desktop? Desktop, I don't think you've tried to plug in the USB port behind the motherboard. You only tried the front USB. If it's a front USB, it's hard to say. The quality of the chassis is not good, or the front USB and audio cable are not connected well, or some front USB expansion interfaces on the motherboard have insufficient power.

You can unplug these first. If this problem persists, turn it on, and don't plug in USB or anything like that. It's not surprising that some hardware and other things are incompatible. If you really need to boot with USB, changing the motherboard should solve it.

At the same time, I want to ask whether the above two friends are both computer experts. It's so complicated to think of it, even the CMOS settings have been thought of, but have you not looked at the problem seriously? People say that the boot has passed the XP scrolling interface, that is, all external things are loaded. You are welcome to use it. Obviously, this is not a matter of boot order. I'm not saying that my answer will definitely solve the problem, but at least I look at the problem carefully.

4. What if the computer is broken?

1, try to start the computer. After playing the computer card, press F8, safe mode, cursor selection: last correct configuration, enter, enter, press!

2。 If not, enter the safe mode, enter the car, and after reaching the desktop, use Jinshan first aid kit to kill virus. Check the Jinshan first aid kit: check Extended Scan, scan now, deal with it immediately, and restart the computer!

4。 No more, unplug the video card and memory stick, eraser, brush it again, clean the slot dust and fan, replace the memory stick and so on!

5。 Check whether there are similar functions and redundant similar software, such as various players and antivirus software.

Wait, uninstall the extra ones, leaving only one, because similar software is incompatible with each other!

6。 Nothing more, download the "Drive Life" upgrade: graphics card driver!

7。 If it still doesn't work, you need to "restore with one button" or "reinstall the system"!

8。 There is something wrong with the hardware, send it for repair!

5. What if the computer breaks down?

Fault phenomenon 1: After the power is turned on and the power button is pressed, the computer does not move.

Analysis: At this time, the power supply should supply power to the motherboard and hardware. Nothing indicates that there is something wrong with the power supply. (Including the power supply part of the motherboard) Check ideas and methods: 1. Please check whether the power socket is normal and the power cord is normal.

2. If there is a problem with the power supply of the chassis, please check whether there is a standby voltage of 5 volts and whether the connection between the motherboard and the power supply is loose. If the voltage cannot be measured, you can find a power supply to change it. 3, the motherboard problem, if the above two are no problem, then the possibility of motherboard failure is relatively large.

First check whether the connection between the motherboard and the power-on key is loose and whether the switch is normal. You can try to short-circuit the switch with wires.

If not, we have to try to change the motherboard. (Note: Try to find a motherboard with the same model or chipset, because other motherboards may not support your CPU and memory. ) symptom 2: press the power-on key, the fan rotates, but there is no image on the display, and the computer cannot enter the normal working state.

Analysis: The rotation of the fan indicates that the power supply has been started, the monitor has no image, and the computer cannot enter the normal working state, indicating that the computer failed the system self-test and the BIOS settings of the motherboard were not output to the monitor. The fault should be in the motherboard, graphics card and memory. But sometimes poor power supply and monitor damage can also lead to this failure.

Thoughts and methods of investigation: 1. If there is an alarm sound, there is something wrong with the self-inspection. The alarm sound is set by the BIOS on the motherboard.

There are two kinds of BIOS, AMI and AWARD. Most motherboards use bonus BIOS.

AWARD's BIOS is set to: long tone keeps ringing: the memory card is not inserted tightly. One short: the system starts normally.

Disadvantage 2: CMOS settings are wrong and need to be reset. One long and one short: memory or motherboard error.

One long and two short: there is something wrong with the monitor or graphics card. One long and three short: keyboard controller error.

One long and nine short: FLASH RAM or EPROM error in motherboard BIOS. The BIOS of AMI is set to: One Short: Memory refresh failed.

Two shortcomings: memory ECC check error. Three short: the system basic memory check failed.

Four Shorts: System clock error. Five short: CPU error.

Six short: keyboard controller error. Disadvantage 7: System real mode error.

Eight short: display memory error. Nine short: BIOS chip check error.

One long and three short: memory error. One long and eight short: the monitor data cable or graphics card is not plugged in properly.

2. If there is no alarm sound, the speaker may be broken. Please follow the following steps. A. Check the memory, take it out, wipe the pins with rubber, and insert it into another slot for debugging.

If there are more than two shared memories, please use only one memory for debugging. B, check the video card, check whether the video card is plugged in, take it out and use an eraser to check the pins, and then try the machine again.

Then unplug the connection between the video card and the monitor, and try the machine again to see if it will enter the next self-check. If possible, try replacing the video card.

C, check the motherboard, first take the motherboard out and put it on an insulated plane (such as books or glass), because sometimes the chassis deformation will cause poor contact between the motherboard slot and the board card. Check whether there is any foreign matter in each slot of the motherboard and whether the gear is oxidized and discolored. If you find that one or two gears are different in color from other gears, it must be caused by oxidation or dust. Please scrape off the gear surface with a knife, then plug in the circuit board before debugging.

Then check whether the wiring between the motherboard and the buttons is normal, especially the hot start button. Finally, try to reset the BIOS by discharging.

The method is to remove the button cell from the motherboard, and then install it five minutes later, or directly install the battery backwards for two seconds, and then try the machine to see if it is normal. If possible, try replacing the motherboard.

D, check the CPU, if it is caused by CPU overclocking, then resetting the above BIOS should solve this problem, if it is not overclocking, then check whether the fan is normal, if it is not, try replacing the CPU. E, the power supply is not good also can appear this kind of phenomenon, conditional try to replace the power supply.

F. If the above methods can't solve the problem, please unplug all hardware except CPU, motherboard, power supply, memory and graphics card, and then try the machine to see if it is normal. If it is normal, after eliminating the possibility of power supply and motherboard problems, solve it with the following method of fault phenomenon 4.

If the debugging is not normal, try to replace these components separately. Symptom 3: There is no image on the monitor after booting, but the machine reads the hard disk. Judging from the sound, the machine has entered the operating system.

Analysis: This phenomenon shows that the host is normal, and the problem lies in the monitor and graphics card. Inspection ideas and methods: check whether the connection between the monitor and the graphics card is normal and whether the connector is normal.

If possible, try replacing the video card and monitor. Symptom 4: Display the graphics card and motherboard information after booting, but the self-check process stops when it reaches a certain hardware.

Analysis: The information display of motherboard and graphics card shows that the internal self-check has passed, and the motherboard, CPU, memory, graphics card and monitor should be normal (but improper BIOS setting of motherboard, poor memory quality and unstable power supply can also cause this phenomenon). The problem lies in the possibility of other hardware.

Generally speaking, the BIOS self-check can't be found if the hardware is broken, but the next self-check can be carried out. If the self-check is stopped due to hardware reasons, the fault is serious, and it may be that there is something wrong with the hardware circuit. ). Inspection ideas and methods: 1. To solve the problem of improper setting of the motherboard BIOS, you can use the method of discharging, or enter the BIOS to modify it, or reset it to the factory setting (refer to the motherboard manual for steps).

One thing to note about the modification is that in BIOS settings, if the alarm item of keyboard and mouse is set to stop self-checking when there is a fault, this phenomenon will also occur if the keyboard and mouse are broken. 2. If you can understand the process of self-checking, generally speaking, the BIOS will stop working when it detects a piece of hardware, so it is likely that the hardware is out of order. You can unplug the power cord and signal cord of this hardware and start it to see if it can enter the next self-check. If yes, there is something wrong with this hardware.

3. If you can't understand the self-check process, please unplug all power and signal lines of floppy drive, hard disk and CD-ROM drive, and unplug all boards such as sound card, modem and network card (except the memory of graphics card). Disconnect all external devices such as printers and scanners.

6. The computer won't start. What should I do?

Startup fault is the most common fault in computer system, which is closely related to computer accessories such as monitor, graphics card, motherboard, CPU and memory stick.

First, the failure analysis of starting a black screen In the startup failure of a computer, the most prominent performance is that the screen is black when starting, without any prompts. This kind of fault is generally difficult to identify, mainly related to monitors and graphics cards; Failure of system mainboard, CPU, cache, memory stick, power supply and other components can also lead to black screen.

1. Self-check black screen failed. After the machine is turned on, the indicator light on the main panel lights up, and the fan in the machine rotates normally, but the display screen does not display. When the computer is turned on, the three indicator lights in the upper right corner of the keyboard do not flash, and the "click ……" sound from the self-test memory and the alarm sound from the PC horn cannot be heard.

It can be seen from the fault phenomenon that the host power supply is basically normal (the host power supply fault is not ruled out), but it crashed when the self-test program in BIOS was not started. You should mainly check the monitor, graphics card, memory, CPU and motherboard.

Because there is no prompt message of not self-checking the black screen fault, usually only the "minimum system method" can be used for inspection and handling. The "minimum system method" refers to the minimum system consisting of basic equipment such as motherboard, memory stick, CPU, graphics card, monitor, power supply, etc. After inspection, the remaining minimum system can work normally, and then other equipment can be further inspected.

2. Insufficient power supply leads to black screen failure. After adding a large-capacity hard disk, the power indicator lights up, but the screen is dark and cannot be started. Since only one hard disk is added, let's start with the hard disk.

Plug in the main boot hard disk interface cable, and after replacing the data cable, it still can't start, but when the hard disk is taken out, the computer can start again. It is no problem to take this large-capacity hard disk to other computers for testing, so it can be inferred that the hard disk is normal.

So what is the reason for the black screen? This is because the hard disk is added with the IDE interface and power interface of the computer system, and the IDE interface is fine (the IDE interface can also cause a black screen if it is reversed), so it can be determined that it is a power configuration problem of the power supply. Determine the power supply problem, and replace the original power supply with high power to eliminate the fault.

3.CPU damage leads to black screen failure. The computer has been running normally, and there is no sign of CIH virus attack. The user once removed the CPU and installed a fan on the CPU radiator. Results The computer was turned on with a black screen, without self-checking. Uncover the cover of the chassis and observe that the hard disk and CD-ROM lights are on at the moment of startup, and the CPU fan (CPU fan interface connected to the motherboard) is also operating normally. Tested by multimeter, the output of 12V and 5V of the power supply is normal, so the power supply problem can be eliminated first.

Remove and reinstall the CPU, memory, graphics card and other components of the machine to ensure that they are installed in place and in good contact. Restart, the fault remains, and the problem of poor contact is eliminated.

Then take out the sound card, optical drive, hard disk, etc. Only the CPU, memory stick and graphics card are left on the motherboard to form a minimalist system. At this point, the startup screen still does not appear. At this point, it can be determined whether the fault is caused by CPU, memory or motherboard.

Careful observation of the replaced CPU shows that there are deep scratches on the two pins of the CPU, which may have been cut off. So I carefully welded the two pins with a soldering iron. When I finished, I plugged the CPU back into the original motherboard. This time it finally started normally, and all the problems were solved.

4. Memory damage leads to black screen failure. The screen is not displayed, and there is a black screen phenomenon. There is no response when you hit any key (the display and the host power indicator light are on), and no self-inspection alarm sound can be heard. Sometimes it can work normally. With the latest version of KV 3000, it is found that the hard disk is nontoxic. But if you turn it off or start it hot, sometimes the screen will be black.

One minute it's normal, the next it's not. Because there is no display on the screen, consider whether there is a problem with the display first.

Check the monitor with the replacement method first, no problem. So I switched the graphics card to another computer, turned it on and the display was normal.

Then I suspected that the PCI expansion slot was in poor contact, so I replaced this good graphics card with another expansion slot, and the fault remained. Another slot, still no response.

Subsequently, the motherboard was removed and carefully checked and tested with a multimeter, and no fault was found. Insert a good ISA bus graphics card into the ISA expansion slot, turn it on, and the fault disappears.

Unplug the video card and restart the computer. I found that I didn't hear the fault alarm sound of the graphics card during the host self-test, and it was suspected that it was related to memory. Unplug the memory module, reverse the order, and then reinstall it. First, install original memory modules 3 and 4, and then restart the computer.

The screen shows that the memory is 8MB (4MB each), and the original article 1 and article 2 are installed after shutdown. When the fault occurs again, the third article is replaced by article 1, which is normal, and the fourth article is replaced by the second article. The fault occurred, and it turned out to be the problem of the fourth memory. From the analysis of the memory stick, it can be concluded that the individual chips of this memory stick are unstable or of poor quality, which leads to errors when the computer starts addressing.

The second is the fault analysis in startup, which solves the fault of starting the black screen. Let's talk about other faults in the startup. Compared with the black screen fault, because the display screen is not completely black, sometimes there will be an error prompt on the screen, so as long as you can understand the following typical faults, it will be much easier to deal with.

The 1. reset key is damaged, so the computer cannot be started. The same phenomenon appears again after a period of restart.

After several restarts, the machine does not perform self-test at all. At first, I thought the hard disk or card was inserted incorrectly. I opened the chassis, plugged in the hard disk and graphics card again, and turned it on again, but there was still no response. It's no use changing the memory stick.

Then I suspect that there is something wrong with the power supply. After the inspection, the power supply is working, and then measure the output voltage of the power supply with a multimeter. Everything is normal, and it is judged that there is something wrong with the motherboard. After inspection, the motherboard has no obvious loose burn marks.

Then unplug everything that can be unplugged from the motherboard (CPU, memory, power plug, and graphics card can't be unplugged), and the self-test passed, proving that there is no problem with the motherboard. Finally, it was recovered in turn, and finally the reason was found out: it turned out that the "reset" button on the chassis was broken, and it did not bounce back after being pressed, and it was always in a short circuit state. No wonder this machine can't start.

2. Two-in-one sound card.