How does the computer frequently freezes?

The computer frequently freezes how to do





computer frequently freezes how to do? Random fault is a common fault encountered in the process of computer use, due to the failure of the crash is uncertain, the nature of the operation is not fixed, and the crash occurs, the phenomenon is not uniform, so the scope of the fault occurred is not easy to determine, to repair work brought a certain degree of difficulty.





according to a large number of maintenance cases, the reason for the random crash failure is mainly the following three aspects:





one, environmental factors





environmental factors have a great influence on the normal operation of the machine. Computer requirements for the environment mainly include: temperature, humidity, power network interference, electromagnetic impact, external vibration impact, electrostatic, grounding systems, power supply system and so on. In particular, temperature, humidity, static electricity, grounding systems, power supply system on the normal operation of the machine has the greatest impact. Because of the machine working environment, such as dust, humidity caused by the circuit between the circuit short-circuit or plug-and-pull parts of poor contact, it is possible to cause system panic. According to the actual maintenance statistics, the random fault caused by environmental factors accounted for about 10% of the total number of failures.





second, software reason




The random crash caused by
software system includes two kinds of cases. One is the virus damage, although sometimes through cold, hot start again to start the machine, but the operation will soon panic. Second, the application software and operating systems are not fully compatible, there is conflict between them or the inherent characteristics of the hardware conflict, the majority of the crash has no keyboard response, can only start the machine again through cold start.





for software reasons for the random failure of the inspection method, you can use a clean boot disk reboot after the machine, and then run anti-virus software to remove the virus. For the application software and operating system conflict, it is recommended to modify the program configuration and change the machine hardware configuration combined method to solve. According to the actual maintenance statistics, the random fault caused by software causes is about 20% of the total number of failures.





Three, the hardware reason





hardware system caused by the panic, mainly due to the internal components of the machine quality, compatibility or improper matching caused. Usually includes:





1. Pluggable chip contact failure. There are some pluggable chips on the motherboard bad contact, this kind of failure is very easy to happen in CPU chips, memory chips and a variety of expansion slots, in addition, the AGP expansion slot is commonly inserted problems.





2. The chip working time series does not match. In a circuit if several chips work together to complete a function, and the execution speed between several chips does not match, when a signal in the chip through the logic transformation, transmission of the required delay time is relatively long, it is easy to generate timing failure. or sequential circuit control time relationship requirements are more stringent, occasional sequential signal drift, this situation is most common in the assembly of compatible machines. In addition, due to the use of different manufacturers of cards or chips are not fully compatible with the phenomenon of high clock frequency, but also cause the crash.





3. Poor thermal stability. The so-called thermal stability is the machine at the beginning of the normal operation, after a period of time, with the chip temperature rise, began to appear panic. After the shutdown, cooling after a period of time after the boot and can work, and then the panic occurred. The main reason is that the quality of the component itself does not pass.





4. Poor chip driving ability. Because each chip's fan out value is fixed, in the circuit design requires the chip output signal to drive the number of chips must be less than the allowable fan out value. If the chip's fan out value does not meet its rated index, when the system or a circuit connected to more equipment, will cause the chip work panic. This failure often occurs on the motherboard's I/O interface, memory address, or data-driven chip.





5. Poor anti-interference ability. Chip power cord and ground wire on the printed circuit board wiring width too small, line and line between the distance too close or the chip between the level of mismatch, so that the transmission signal has "oscillation" or "reflection" caused by signal interference, so that the chip has anti-interference ability and cause system panic. According to the actual maintenance statistics, the random fault caused by the hardware is about 70% of the total number of failures, which is the main reason of the stochastic failure, and also the part of this article.





analysis and maintenance method of stochastic failure





the principle of checking for this type of failure is that firstly, according to the fault phenomenon, deduce the nature of the fault, then according to this inference, using multimeter, logic pen, oscilloscope and other tools to check the hardware line on the corresponding signal whether there is random interference or timing drift, if there is to find the appropriate hardware for repair and replacement.





first check to see if there is a contact failure. Remove various expansion cards from the shutdown state with the finger card edge gently bend, beat, and then in the power-on state, with the finger press the edge of the card, CPU sockets on the motherboard, memory, and a variety of plugs or sockets, if in a certain case the machine can start, it indicates that the contact of bad fault.





If the repeated test proves that it is not a contact fault, it is necessary to check whether the timing fault of the circuit is controlled. Key check:





1. System control circuit chip. Mainly address bus select、read and data bus chip, ale address latch signal, as well as the motherboard on the south, North Bridge chip and other door array chip.





2. System memory control circuit, drive circuit. The main is the ram of the line-select communication number RAS, the column-selected communication number CAs, the row address conversion control signal and the memory data readout drive, memory chip speed matching relation.





3. The system of various clock signal circuits, mainly sysclk, PROCCLK, PCLK, DMACLK.





through the use of more than 100MHz high-frequency oscilloscope to check the above signal, hoping to find a signal in a moment of abnormal state, such as timing drift or burr and other interference signals, found after the corresponding chip to replace.





third is the thermal stability difference is another major manifestation of the failure at any time, with the advent of summer or overclocking use of CPU, such failures become more frequent. The inspection can use hair dryer distance open chassis 20 cm ~30 centimeters of heating, when the chassis temperature rise to 60℃~70℃ around, the fault may begin to appear frequently. When the machine is placed in the air-conditioned room of the 18℃~25℃, if the failure rate is greatly reduced, it is determined that the thermal stability difference fault. Then use the oscilloscope motherboard data bus, address bus, control chip output waveform inspection, if found to have obvious interference signal, then find the corresponding chip to replace.





Four is one of the common reasons for the random fault caused by the mutual interference between signals and the poor chip driving ability. In the maintenance found that this type of failure is more than 74FXX chips and 74LSXX, alsxx between the chips.