1, the virus "shock wave" virus will also prompt the system to start automatically after 60 seconds. Trojan horse programs remotely control all activities of your computer, including restarting your computer. Remove viruses, Trojans or reinstall the system.
2. The system file is damaged. System files are damaged, such as basic files such as KERNEL32.DLL in Win2K and fonts in Win98 FONTS directory when the system is running, and the system will be forced to restart when it is started. Solution: cover the installation or reinstall.
3. Timing software or task planning software works. If you restart or load some working programs in the Planning Taskbar, the computer will start again. In this case, we can open the "startup" item, check whether there are unfamiliar execution files or other scheduled working procedures, and then filter them before starting the inspection. Of course, we can also directly enter the "Msconfig" command in "Run" to select the startup item.
Second, the hardware.
1, chassis power supply is insufficient, DC output is impure, and dynamic response is slow. Users or installers often ignore the power supply and use cheap power supply, which is one of the biggest suspects that lead to the automatic restart of the system.
(1) The output power of the power supply is insufficient. When running software that takes up a lot of CPU resources such as large 3D games, when the CPU needs high power supply, the power supply is overloaded due to insufficient power supply, and the output is stopped. After the power supply stops outputting, the load is lightened and the power supply is resumed. Because the protection/recovery time is very short, the performance given to us is that the host automatically restarts.
(2) The DC output of the power supply is impure, and the digital circuit requires pure DC power supply. When the harmonic content in the DC output of power supply is too large, it will lead to errors in the operation of digital circuits, which are manifested as frequent crashes or restarts.
(3) 3) The workload of CPU is dynamic, so is the requirement for current, which requires dynamic response speed. Some poor quality power supplies have long dynamic response time, which will also lead to frequent crashes or restarts.
(4) Update the equipment (high-end graphics card/large hard disk/graphics card). After adding the equipment (burner/hard disk), the power exceeds the rated output power of the original power supply, which will lead to frequent crashes or restarts. Solution: Now replace the high-quality and high-power computer power supply.
2. Memory problems caused by poor thermal stability of memory, chip damage or incorrect settings all have a high probability of system restart.
(1) The thermal stability of the memory is poor, and it can work normally when it is turned on. When the memory temperature rises to a certain temperature, it will not work normally, resulting in a crash or restart.
(2) When the memory chip is slightly damaged, the boot can pass the self-check or enter the system, and it will restart or crash when running some software with large throughput. Solution: Replace the memory.
(3) Setting the CAS value of the memory too small will also lead to the instability of the memory, leading to the automatic restart of the system. Generally, it is best to use the default settings of BIOS, and don't change them yourself.
3. The 3.CPU temperature is too high or the cache is damaged.
(1) Excessive CPU temperature usually leads to a protective automatic restart. The reason for the high temperature is basically because the chassis and CPU are not well cooled. The reasons for poor heat dissipation of CPU are: low thermal conductivity of radiator material, foreign objects (mostly warranty cards) between radiator and CPU, low fan speed, too much dust on fan and radiator, and so on. In addition, the temperature probe under the CPU of P2 and P3 motherboards is damaged or the temperature measuring circuit inside P4 CPU is damaged, the BIOS on the motherboard has a BUG and temperature measurement is not allowed under some special circumstances, and the CPU protection temperature set in CMOS is too low, which will also cause protection restart.
(2) The damage of the first-level and second-level caches inside the CPU is a common failure of the CPU. Those who are slightly damaged can still start and enter the system, and will restart or crash when running some Qualcomm software (media playing, games, plane 3D drawing).
Solution: Shield the second-level cache (L2) or the first-level cache (L 1) in CMOS, or replace the CPU to eliminate it.
4. Automatic restart caused by 4.AGP graphics card and PCI card (network card, cat)
(1) The external card does not work properly or its quality is poor, which leads to the failure of the reset signal of AGP/PCI bus and the system restart.
(2) There is a situation that the system restarts due to the looseness of the graphics card and the network card.
5. When the parallel port, serial port and USB interface are connected to a faulty or incompatible external device, they will automatically restart.
(1) peripheral equipment is faulty or incompatible, such as damaged parallel port of printer, short circuit of one pin to ground, short circuit of USB device to ground, incompatibility between pin definition and signal level, etc.
(2) When the external equipment is hot-plugged, the jitter is too large, resulting in an instantaneous short circuit of the signal or power supply.
6. The internal circuit or chip of the optical drive is damaged.
The optical drive is damaged, and most of them can't be read/engraved. There is also a sudden restart of the host due to internal circuit or chip damage during work. The CD-ROM drive itself is poorly designed, and there is a Bug in FireWare. It also causes a reboot when reading the disc.
7. Reset switch on the front panel of the chassis The reset key on the front panel of the chassis is actually a normally open switch, and the reset signal on the motherboard is a +5V level signal, which is connected to the reset switch. When the switch is closed, the +5V level is grounded, and the signal level drops to 0V, which triggers the system to reset and restart, and the reset switch returns to the normally open position, at which time the reset signal returns to the +5V level. If the reset key is damaged, the switch is always in the closed position, and the reset signal is always 0V, the system will not be able to power on for self-test. When the elasticity of the reset switch is weakened and the button is not easy to bounce when pressed, the switch will be easily closed with a slight vibration. Resulting in a system reset and restart.
Solution: Replace the reset switch. There is also a short circuit in the reset switch lead in the chassis, which leads to the automatic restart of the host.
8, motherboard failure
It is rare for the motherboard to cause an automatic restart. Generally, the circuit related to reset is faulty; Socket and slot have virtual welding and poor contact; Individual chips, capacitors and other components are damaged.
Third, other reasons.
1, power supply voltage is unstable.
(1) The working voltage range of computer switching power supply is generally 170V-240V. When the power supply voltage is lower than 170V, the computer will automatically restart or shut down. Solution: add voltage regulator (not UPS) or 130-260 V wide switching power supply.
(2) If the power-consuming appliances such as computers, air conditioners and refrigerators use patch panels, when these appliances are started, the voltage supplied to the computers will be greatly affected, which is often manifested by system restart.
The solution is to separate their power cords.
2. Strong magnetic interference Don't underestimate electromagnetic interference. Many times our computer crashes and restarts are also caused by interference. These disturbances not only come from the internal CPU fan, chassis fan, graphics card fan, graphics card, motherboard and hard disk, but also from the external power cord, inverter air conditioner and even large equipment such as cars. If our host has poor interference performance or poor shielding, the host will restart unexpectedly or crash frequently.
3. Incorrect connection of AC power cord. Some users directly ground the zero line of the power supply line (not connected to the zero line of the watt-hour meter), which leads to automatic restart, because the interference signal is introduced from the ground line.
4. The plug-in or power socket is of poor quality and poor contact. After the power socket is used for a period of time, the elasticity of the reed slowly loses, which leads to poor contact between the plug and the reed, constant change of resistance and fluctuation of current, and the system will naturally be unstable. Once the current fails to meet the minimum requirements for system operation, the computer will restart.
The solution is to buy a good socket with qualified quality.
5. Too much dust causes the reset line of the motherboard to be short-circuited and automatically restarted.
Fourth, some examples.
1, a bad example of CPU secondary cache
A 865PE-Neo2, P4 2.8c, KingMax DDR400, Windows XP system. Automatically restart when playing games, replace memory, graphics card, power failure is still the same. Turn off the secondary cache in the BIOS, which runs slowly, but will not restart automatically. Then replace the CPU(P4 3.0e) for troubleshooting. Finally, the CPU returned to the factory. A KT4AV, AMD XP 1800+, DDR333, Windows XP system. Unable to enter the system, as long as XP boot screen will automatically restart, replace memory, graphics card, power failure is still the same. Enter the BIOS, close the secondary cache of CPU, save and exit, then restart, and then enter the system normally. Finally, replace the CPU for troubleshooting.
2. Example of power failure
Two compatible computers, one CPU is Athlon XP 1800+, the other CPU is P4 2.0GHz, and the power supply is Century Star. When the computer runs at full capacity for a period of time, it will automatically restart frequently. It is normal to use it for general work such as document editing and surfing the Internet, and problems only occur when a large number of calculations are carried out. Suspected CPU temperature is too high, and the test shows that the temperature is normal. Replace the memory and the graphics card is still faulty. In addition, it is found that one of the hard disks has a bad track, and the fault still exists after replacing the hard disk and reinstalling the system. Hard disk tracks are basically caused by poor power supply. So put on the Queen of Hangjia Lengjing, and the fault disappeared.
3. Examples of poor graphics card contact
Moved and reconnected a compatible computer with 845PE Neo-L motherboard, P4 2.0G CPU, 80G hard disk and Xiaoyingba 5200 graphics card. After the motherboard LOGO flashes, the WINDOWS XP startup screen appears, and then the cursor flashes. Everything is all right, but when I was about to enter the system, the computer suddenly restarted with a beep, which happened several times. Check the computer wiring, there is no problem. Select safe mode at startup to enter normal operation of the system. After restarting, enter the BIOS to check the CPU temperature. In the normal range, it is ruled out that the CPU is overheated and causes a restart. Because it is normal before moving, consider whether the connector is loose due to the vibration during handling. Open the chassis, check the graphics card, and find that it is not tightly inserted. It takes a lot of effort to plug it in again and restart the troubleshooting parts.
4. Examples of memory mismatch When the motherboards of 865PE, K7N2 and K8N use the 200MHz front-end bus, it is best to use DDR400 with CL=2.5. DDR400 with CL=3 often fails to restart automatically. At this time, the memory drops to DDR333, and the fault disappears. There are too many such examples. Users are advised to use DDR400 with CL=2.5.
5. Examples of neutral grounding
There is a decoration design company that frequently restarts 20 computers automatically, and it is getting worse and worse, and finally it can't work normally. Please ask the author to have a look.
Fault phenomenon: More than 20 computers automatically restart every three or two minutes in a large studio on the second floor. Sometimes all computers restart at the same time, sometimes one by one in sequence, and sometimes every 1 /2 in sequence, which is very rhythmic.
Fault analysis: users have reported this phenomenon for a week. It was not serious at first, but it has been serious in the past two days and can no longer be used. At the same time, there is a computer on the 1 floor that does not restart automatically. According to the author's analysis, 1 is unlikely to be the problem of the computer itself. 2. So rhythmic, it must be external interference, and the biggest interference source is the power cord. So I checked the power supply line and found the distribution box. I found that the zero line of the power supply line on the second floor was disconnected at the watt-hour meter and directly connected to the ground wire. 1 The computer that does not restart automatically is connected to the lighting circuit, and the zero line is normal. At the same time, I learned that a construction site started construction a week ago, and the interference signals generated by various electrical equipment such as cranes on the site are connected in series with the users on the same power grid line.
Troubleshooting: change to normal zero line, troubleshooting.