First, the software
1, the virus "shockwave" virus attack will also prompt the system will automatically start in 60 seconds. Trojan horse program from a remote control of all the activities of your computer, including let your computer restart. Remove the virus, Trojan, or reinstall the system.
2, system file corruption System files are damaged, such as Win2K under the KERNEL32.DLL, Win98 FONTS directory under the font and other basic system runtime files are damaged, the system will be unable to complete the initialization at startup and forced to restart. The solution: overwrite the installation or reinstall.
3, timing software or scheduled task software plays a role If you set up in the "scheduled task bar" to restart or load some of the work program, when the time comes, the computer will start again. In this case, we can open the "Startup" item, check if there are any unfamiliar files or other timed programs in it, and block them before turning on the computer. Of course, we can also enter "Msconfig" command directly into "Run" to select the startup items.
Two, hardware
1, chassis power supply power, DC output is not pure, slow dynamic response. Users or installers often do not pay attention to the power supply, the use of inexpensive power supply, so it is one of the biggest suspects of causing the system to restart automatically.
(1) power supply output power is insufficient, when running large-scale 3D games and other software that take up a large amount of CPU resources, the CPU needs to power supply, power supply power is not enough and overload caused by power protection, stop output. After the power supply stops output, the load is reduced, at which time the power supply starts again. Because the protection/recovery time is very short, so the performance to us is the host automatically reboot.
(2) power supply DC output is not pure, digital circuitry requires pure DC power supply, when the DC output of the power supply in the harmonic content is too large, it will lead to the digital circuitry work error, the performance is a frequent crash or reboot.
(3) CPU workload is dynamic, the current requirements are also dynamic, and requires a rapid dynamic response. Some poor quality power supplies have long dynamic response times, which can also lead to frequent crashes or reboots.
(4) update the equipment (high-end graphics cards / large hard disk / video card), increase the equipment (burner / hard disk), the power exceeds the rated output power of the original power supply will lead to frequent crashes or reboots. Solution: Now change the high-quality high-power computer power supply.
2, memory thermal stability is poor, chip damage or setup errors Memory problems lead to system reboot to system reboot is relatively large.
(1) Memory thermal stability is poor, boot can work normally, when the memory temperature rises to a certain temperature, it can not work properly, resulting in crash or reboot.
(2) When the memory chip is slightly damaged, the boot can pass the self-test, and can also enter the system, when running some of the throughput software will restart or crash. The solution: replace the memory.
(3) Setting the CAS value of the memory too small can also lead to memory instability, causing the system to restart automatically. The best way to do this is to use the default settings in the BIOS and not to change them yourself.
3, the CPU temperature is too high or the cache is damaged
(1) The CPU temperature is too high often cause protective automatic reboot. The reason for the high temperature is basically due to the chassis, poor CPU heat dissipation, poor CPU heat dissipation causes: low thermal conductivity of the radiator material, radiator and the CPU contact surface between the foreign body (more than the warranty post), the fan speed is low, the fan and the radiator accumulates too much dust and so on. There are P2, P3 motherboard CPU below the temperature probe damage or P4 CPU internal temperature measurement circuit is damaged, the motherboard BIOS has a BUG in a special condition of the temperature measurement is not allowed, CMOS set in the CPU protection temperature is too low, etc. will also cause a protective reboot.
(2) CPU internal first and second level cache damage is a common CPU failure. Damage to the degree of light, or can start, enter the system, when running some of the throughput of the software (media playback, games, flat 3D drawing) will restart or crash. Solution: Shield the second level cache (L2) or first level cache (L1) in CMOS, or replace the CPU to rule out.
4, AGP graphics card, PCI card (network card, cat) caused by the automatic reboot
(1) the external card workmanship is not standard or poor quality, triggered by the AGP/PCI bus RESET signal malfunction caused by the system reboot.
(2) There are also instances where the graphics card and network card are loose, causing the system to reboot.
5, parallel port, serial port, USB interface access failure or incompatible external devices automatically reboot
(1) external device failure or incompatibility, such as the printer's parallel port is damaged, a pin shorted to the ground, the USB device is damaged shorted to the ground, the pin definition, the signal level is incompatible.
(2) When hot-plugging external devices, the jitter is too large, causing an instantaneous short circuit of the signal or power supply.
6, the internal circuitry of the optical drive or chip damage
Optical drive damage, most of the performance is unable to read the disk / disk. There are also cases where the internal circuitry or chip is damaged causing the host to suddenly reboot during the work process. The optical drive itself is poorly designed, and FireWare is buggy, which can also cause a reboot when reading a CD-ROM.
7, the chassis front panel RESET switch problem The chassis front panel RESET button is actually a normally open switch, the motherboard RESET signal is +5V level signal, connected to the RESET switch. When the switch is closed at the moment, the +5V level conducts to ground, the signal level drops to 0V, triggering a system reset and restart, the RESET switch returns to the normally open position, and at this time, the RESET signal returns to the +5V level. If the RESET key is damaged, the switch is always in the closed position, the RESET signal is always 0V, the system can not power up and self-test. When the RESET switch elasticity is weakened and the button is not easy to pop up when pressed, the switch will be easy to close with a slight vibration. This leads to the system reset reboot. Solution: Replace the RESET switch. There are also short-circuited RESET switch leads in the chassis that cause the host to restart automatically.
8, motherboard failures
The motherboard leads to automatic reboot instances are rare. Generally, the circuitry related to RESET is faulty; sockets and slots have soldering, poor contact; individual chips, capacitors and other components are damaged.
Third, other reasons
1, the utility voltage instability
(1) The computer's switching power supply operating voltage range is generally 170V-240V, when the utility voltage is lower than 170V, the computer will automatically restart or shut down. Solution: Add a voltage regulator (not UPS) or 130-260V wide switching power supply.
(2) computer and air conditioning, refrigerators and other large power consumption appliances *** with a plug board, when these appliances start, the voltage supplied to the computer will be greatly affected, often manifested as a system reboot. The solution is to separate their power supply lines.
2, strong magnetic interference Do not underestimate the electromagnetic interference, many times our computer crash and restart is also due to interference caused by these interferences both from the chassis inside the CPU fan, chassis fan, graphics card fan, graphics card, motherboard, hard disk interference, but also from the outside of the power line, inverter air conditioning and even automotive and other large equipment interference. If our host's interference performance is poor or poor shielding, there will be a host of unexpected restart or frequent crash phenomenon.
3, AC power lines connected to the wrong Some users of the zero line of the power supply line directly to ground (do not go to the zero line of the meter), resulting in automatic restart, the reason for the introduction of interference signals from the ground.
4, the poor quality of the plug or power outlet, poor contact. Power socket after a period of time, the reed elasticity is slowly lost, resulting in poor contact between the plug and the reed, the resistance is constantly changing, the current with the ups and downs, the system will naturally be very unstable, once the current does not reach the minimum requirements of the system to operate, the computer restarted. The solution, buy a good quality socket.
5, too much dust leads to the motherboard RESET line short circuit caused by automatic restart.
Fourth, some examples
1, CPU L2 cache bad example
A 865PE-Neo2, P4 2.8c, KingMax DDR400, Windows XP system. In the game automatically restart, replace the memory, graphics card, power supply failure remains. Turn off the L2 cache in BIOS, it runs very slowly, but does not restart automatically, then replace the CPU (P4 3.0e) to solve the problem. Finally, the CPU was returned to the factory. A KT4AV, AMD XP1800+, DDR333, Windows XP. Can not enter the system, the XP boot screen will automatically reboot, replace the memory, graphics card, power supply failure remains. Enter BIOS and turn off CPU L2 cache, save and exit, restart, can enter the system normally. The last thing I want to do is to change the CPU and get rid of the problem.
2, power failure examples
Two compatible machines, a CPU for the Athlon XP 1800 +, a CPU for the P4 2.0GHz, the power supply for the Century Star power. When the computer is running at full capacity for a period of time, it frequently restarts automatically. Usually used for document editing, surfing the Internet and other general work is normal, only when a large number of calculations out of the problem. Suspected that the CPU temperature is too high, the test shows that the temperature is normal. Replacement of memory, graphics card failure remains. In addition to checking the hard disk found that one of the hard disk bad sectors, replace the hard disk reinstallation system failure remains. Hard disk bad sectors is basically caused by bad power supply. The first time I saw this, I was able to get the ball rolling, and I was able to get the ball rolling, and I was able to get the ball rolling.
3, the graphics card poor contact examples
A configuration for the 845PE Neo-L motherboard, P4 2.0G CPU, 80G hard disk, small ShadowBlade 5200 graphics card compatible with the machine because of the move, re-connected to the boot self-test is normal, flashed the motherboard LOGO, WINDOWS XP boot screen, then the cursor flashes, everything is normal! But about the time when the system is about to enter, the computer suddenly "tick" sound restarted, restarted several times are so. Check the computer wiring, no problem. Select safe mode at startup can enter the system, running normal, restart into the BIOS to check the CPU temperature, within the normal range, to rule out the CPU overheating caused by the reboot. Because of moving before moving is normal, consider whether the vibration in the process of moving is loose connectors. Open the chassis, check the graphics card, found that there is no inserted tightly, re-inserted tightly stuck firmly, restart troubleshooting pieces of failure, and a great deal of trouble.
4, memory mismatch example 865PE, K7N2, K8N motherboard in the use of 200MHz front bus, it is best to use CL = 2.5 DDR400. use CL = 3 DDR400 often appear automatically restarted the fault, at this time, the memory down to DDR333, the fault disappears. There are too many such instances. It is recommended that users still use CL = 2.5 DDR400.
5, zero-wire grounding example There is a renovation and design company 20 computers regularly restart automatically, and the more intense, and finally reached the point where it can not work properly. Ask the author to take a look.
Failure phenomenon: more than 20 computers in a large studio on the 2nd floor, every three or two minutes on the automatic restart, sometimes all the computers restart at the same time, sometimes a one by one order to restart, sometimes every 1 / 2 units in order to restart, very rhythmic.
Failure analysis: users reflect this phenomenon has been a week, the beginning is not serious, the last two days serious, has not been able to work. At the same time on the 1st floor there is a computer without the phenomenon of automatic restart. I analyze, 1, it is unlikely that the computer's own problems, 2, so there is a rhyme, it must be outside interference, interference with the largest source of power lines, so check the power supply lines, check the distribution box, found that the 2nd floor power supply line in the meter at the zero line disconnected, and then directly connected to the ground earth ground. 1 floor of the computer that does not automatically reboot is connected to the lighting line, the zero line is normal. At the same time to understand that a week ago near a construction site to start, and the user with a grid line, the construction site of the crane and other power equipment generated by the interference signal through the ground string.
Troubleshooting: Change to regular zero line, troubleshooting.
Troubleshooting: Change to regular zero wire, troubleshooting.