Causes and elimination of common faults of computer power supply
1. There is power output but no display when starting.
Symptoms: The computer has power output, but it does not display when it is turned on.
Analysis and solution: The possible cause of this fault is that the reset signal input by POWERGOOD has insufficient delay time, or POWERGOOD has no output. After starting, measure the output of POWERGOOD with a voltmeter. If there is no +5V output, check the delay element. If it is +5V, replace the delay capacitor of the delay circuit.
2. It will automatically restart every time it is turned on.
Fault: The computer will automatically restart every time it is turned on, and now it can only enter the operating system after repeated self-checking.
Analysis and solution: Boot and restart are usually caused by motherboard failure, and unstable power output may also be the reason. Check these two devices.
3. When the ignition switch is on the chassis, the indicator light showing the power supply flashes at the same time.
Fault symptom: the chassis is on fire and the power indicator of the monitor flashes at the same time.
Analysis and solution: It is probably a power supply problem, because it is difficult for other accessories in the chassis to produce this problem, indicating that the devices inside the power supply are damaged or short-circuited. Go to a professional to repair or replace a new power supply.
The computer will automatically shut down after a few minutes of turning on.
Trouble: the computer is equipped with PENTUM3 700, MSI motherboard, modern 128 MB and Maztor hard disk. Recently, the computer will automatically shut down every few minutes. The indicator lights on the host, CD-ROM drive and monitor are all on, but the fan is running, but there is no response. Only when the power supply is turned off and restarted can it work normally.
Analysis and solution: After the power supply works for a period of time, the heat increases and some components are unstable, which leads to the disconnection of output current, so repair the power supply.
5. Turn on the power switch, and automatically start the host power supply.
Symptoms: The computer startup sequence is reversed. Usually, both the monitor and the host should be started manually, and the power of the host will start automatically when the power switch is turned on.
Analysis and solution: It is probably caused by a problem set in the BIOS. You can set it in the BIOS of the motherboard first, and then turn off the function of listening to a PWERON AFRER POWERFALL option in POSERMANAGERMENT.
6. Before restarting, you must unplug and plug in the power plug.
Trouble: When offline, when checking QQ messages and letters in FOXMAIL, the computer will suddenly shut down. At this time, there is no response to the power switch, so you must unplug the power plug and plug it in again to restart.
Analysis and solution: It is likely that there is something wrong with the automatic protection circuit of the power supply. Check whether the main power supply is stable. In addition, you can use another power supply first to see if it is caused by the power supply itself.
7. Restart when shutdown
Fault phenomenon: it will automatically restart after each shutdown recently until the screen appears. In addition, sometimes it will automatically restart just after entering WINDOWS98.
Analysis and solution: This is because WINDOWS98 has a BUG in the energy control function. If so, you need to install the related shutdown patch of WINDOWS98 to solve this problem. If you restart just after entering WINDOWS98, it is caused by motherboard failure or improper power current output. You can turn off advanced management of power supply in the WINDOWS system control panel.
8. Do not use the power switch of the chassis to turn it off.
Fault phenomenon: We can't completely turn off the power switch on the chassis, but go into hibernation, and soft shutdown is normal.
Analysis and solution: In the computer with ATX architecture, there are obstacles in setting the power switch of the chassis in the power management of the motherboard BIOS. You can set to press the power button on the chassis to turn off the computer, or you can set it to sleep. At this point, if you need to use the power button to turn off the computer, you need to press it for more than 4 seconds to turn it off.
Common faults caused by poor power supply
1. The performance of the CD-ROM drive becomes worse, and disk reading crashes frequently occur, which shortens the service life of the CD-ROM drive.
2. Insufficient power supply voltage causes USB devices such as mobile hard disks to be unrecognizable or can only be recognized occasionally.
3. Insufficient power supply causes the power supply and chassis shell to heat up and the temperature is too high when the host is running.
4. The system often restarts randomly, with blue screen and crash.
5. The hard disk is prone to bad tracks, easy to damage the hard disk, resulting in data loss.
6. When the system load is high, it is easy to crash, and the operation is unstable after overclocking.
7. The system does not start after installing multiple hard disks or optical drives, or it is difficult to start.
8. After installing a high-power graphics card, it can't be started, the game crashes, and the graphics card driver reports an error.
8. Because the filter circuit of inferior power supply cuts corners, the output voltage ripple is large and the sound card is noisy.
9. After entering the system, water ripple interference appears on the display screen. In the long run, it will damage your eyesight.
10. After the computer is started, it will cause interference to other electrical appliances, such as the decline in the definition of the TV set and the appearance of horizontal stripes or mesh patterns.
1 1. Normal USB devices cannot be recognized, which may be related to insufficient power supply voltage.
12. The graphics card is "damaged" due to insufficient power supply.
There are many such inexplicable computer failures, which are closely related to the quality of power supply.
These questions are very common in computer forums, and the questioner occupies many forum pages. It can be seen that the computer failures caused by these power supplies really bother too many people.
Faced with so many problems, will you be as extensive as before when choosing power supply? How can we identify the quality of a power supply?
The computer power supply is actually a power converter, and its function is to convert 220V 50Hz alternating current into various direct currents required by various components in the computer. Most of us don't need to know how power works, but there are some common sense that hardware players should remember:
1.+5V (red line): mainly used for motherboard power supply (including memory). The hard disk signal circuit of CD-ROM drive is also powered by +5V power supply.
2.+ 12V (yellow line): drives the disk drive motor and all fans.
3.+3.3V (orange line): power supply for CPU, motherboard, PCI bus and I/O control circuit. At present, the voltage of CPU and AGP is getting lower and lower, and the new ATX specification has increased the voltage by +3.3, so there is no need to change it from +5V to+3.3V. ..
4.+5Sb (standby, purple line): The voltage is exactly the same as +5V, but it has its own circuit, which has nothing to do with other power supply circuits. As long as the computer is powered on, it can always be turned on whether it is turned on or not. This line is used for some devices that can activate the system, such as remote boot network card.
5.PS-ON (green line): the switch of the operating system to manage the power supply, together with +5VSB, is collectively referred to as soft power supply, which realizes the functions of software on/off and network wake-up. You can short the green line and the black line to start the power supply.
6.-5V (white line)-12V (blue line): Negative voltage is rarely used in current power supply. In the early days, it was used with-12V line for old equipment such as ISA bus and COM port.
7.PG (power supply is good, gray line): PG signal line is connected to the motherboard and controlled by the monitoring software of the motherboard. Before the system starts, internal inspection and voltage test are completed through this line. If there is no PG signal, the system cannot be started.
From the above brief introduction, we can see that even after we turn off the computer, if we don't cut off the AC input of the switching power supply, the standby power supply will always work, and the power supply will still consume about 5 to 10 watts. So the correct way is to unplug the host after shutting down. It is more convenient if there is a switch behind the power supply.
Power output lines of various colors
When the power supply is working, it itself has electricity, so the power supply itself is a "consumer". Moreover, there is loss in power supply conversion, and the energy input from the power supply cannot be converted into the effective energy of all components in the host, so there is a problem of conversion efficiency. Power conversion efficiency = instantaneous output power provided by power supply for host/instantaneous power of input power supply × 100%. The conversion efficiency has little to do with the power of the power supply. The higher the conversion efficiency, the more energy-saving the power supply itself, and the more fully utilized the input alternating current. The conversion efficiency of high-quality power supply is generally above 80%.
All of us should pay attention to the conversion efficiency of power supply when buying power supply, try to choose products with high conversion efficiency, reduce unnecessary power consumption and do our part to protect our green home. High power conversion efficiency also means that the power supply itself generates less heat, which is more conducive to reducing the temperature in the chassis.
That's all we have to talk about today. I'm sure everyone knows. Maybe netizens didn't know much about it before, and they didn't think it was necessary to know about the power supply. In fact, the power supply is like the blood of the whole computer. To ensure the stable operation of the computer, it is necessary to have good input current and stable line safety.
Solutions to Common Faults of Computer Power Supply
There is power output, but there is no display when starting.
Symptoms: The computer has power output, but it does not display when it is turned on.
Analysis and solution: The possible cause of this fault is that the reset signal input by POWERGOOD has insufficient delay time, or POWERGOOD has no output. After starting, measure the output of POWERGOOD with a voltmeter. If there is no +5V output, check the delay element again. If it is +5V, replace the delay capacitor of the delay circuit.
It will automatically restart every time it is turned on.
Fault: The computer will automatically restart every time it is turned on, but now it can only enter the operating system after repeated self-checking.
Analysis and solution: Boot and restart are usually caused by motherboard failure, and unstable power output may also be the reason. Check these two devices.
When the fire in the cabinet is lit, the light of the display power supply flashes.
Fault symptom: the chassis is on fire and the power indicator of the monitor flashes at the same time.
Analysis and solution: It is probably a power supply problem, because it is difficult for other accessories in the chassis to produce this problem, indicating that the devices inside the power supply are damaged or short-circuited. Go to a professional to repair or replace a new power supply.
It only takes a few minutes after the computer is turned on, and it will automatically turn off.
Trouble: the computer is equipped with PENTUM3 700, MSI motherboard, modern 128 MB and Maztor hard disk. Recently, the computer will automatically shut down every few minutes. The indicator lights on the host, CD-ROM drive and monitor are all on, but the fan is running, but there is no response. Only when the power supply is turned off and restarted can it work normally.
Analysis and solution: After the power supply works for a period of time, the heat will increase, and some components will be unstable, resulting in the disconnection of output current. Repair the power supply.
When the power switch is turned on, the host power will be automatically started.
Fault phenomenon: the computer boot order is reversed. Usually, both the monitor and the host should be started manually one by one, and the power of the host will start automatically when the power switch is turned on.
Analysis and solution: It is probably caused by a problem set in the BIOS. You can set it in the BIOS of the motherboard first, and then turn off the function of listening to a PWERON AFRER POWERFALL option in POSERMANAGERMENT.
You must unplug the power plug first and then plug it in before you can restart it.
Fault phenomenon: offline, when viewing QQ messages and letters in FOXMAIL, the computer will suddenly shut down. At this time, there is no response when the power switch is turned on. You must unplug the power plug and plug it in again to restart.
Analysis and solution: It is likely that there is something wrong with the automatic protection circuit of the power supply. Check whether the main power supply is stable. In addition, you can use another power supply first to see if it is caused by the power supply itself.
Restart when shutdown
Fault phenomenon: it will automatically restart after each shutdown recently until the screen appears. In addition, sometimes it will automatically restart when you just enter WINDOWS98.
Analysis and solution: This is because WINDOWS98 has a BUG in the energy control function. If so, you need to install the related shutdown patch of WINDOWS98 to solve this problem. If you restart just after entering WINDOWS98, it is caused by motherboard failure or improper power current output. You can turn off advanced management of power supply in the WINDOWS system control panel.
You can't turn it off with the power switch of the chassis.
Fault phenomenon: When we use the power switch on the chassis, we can't turn it off completely, but enter a dormant state, and soft shutdown is normal.
Analysis and solution: In ATX-based computers, there are obstacles in setting the chassis power switch in motherboard BIOS power management. You can set to press the power button on the chassis to turn off the computer, or you can set it to sleep. At this point, if you need to use the power button to turn off the computer, you need to press it for more than 4 seconds to turn it off.
What are the articles about common power failures of computers?
★ Causes and operation steps of common faults of computer power supply
★ What are the common faults of computer ATX power supply? How to solve it?
★ What are the common problems of notebook power adapter? How to solve it?
★ Computer power failure phenomenon
★ What are the common problems of computer host power supply? What about the solution, charity?
★ What are the faults caused by poor power supply?
★ What are the common faults of notebook computers? What is the solution?
★ A complete collection of solutions to common computer faults.
★ What should I do if the computer restarts frequently due to power failure? What is the solution?