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performance is poor, although the voltage is stable also within the normal allowable range, but because of its output power harmonics in the content is too large, will also lead to frequent host of the crash or restart. For this case, we use a multimeter to test its voltage is normal, it is best to replace a good power supply for replacement removal. Solution: Now for high-quality high-power computer power. 4. Main engine switching power supply plu

insufficient or have trouble to be able to appear afore-mentioned circumstance. For power supply +5v and +12v voltage instability, we can use the multimeter test to judge. Too high and too low are not good, generally within 10% fluctuations can be considered normal situation. For the power supply to provide a shortage of current situation, we can according to their own host of the hard disk, optical drive and related configuration to calculate the fu

operation of the process, you canDue to the internal structure of memory damage, when to select this part as video memory, the chip and the obvious existence of data exchange often error, resulting in the flower screen, black screen, or even the crash phenomenon. In this case, you can replace the same size of memory for checking with the substitution method. Of course, if the video memory is integrated on the motherboard, you can only send repair. Six, capacitance issues Ramdac (Random Acce

. points of judgment/order 1, before the maintenance of the preparation 1) disk data cable; 2 multimeter; 3) virus-checking software. 2, environmental inspection 1 machine peripheral and appearance inspection: A. Mains connection is broken sad, should not be too loose or inserted in place of the phenomenon; B. Whether the host hard drive indicator is correct and shiny, should not be light or often bright phenomenon; C. To observe whe

working properly. 2. Connection failure (1) Check whether the RJ45 interface is made well, RJ45 is the interface form of 10BASE-T network standard, it is now widely used, its inside has 8 trough, the line trough meaning follows the eia/tia568 International standard, in the 10BASE-T network 1, 2 line for Send line, 3, 6 line is the receiving line. When the two machines are connected, the 1, 3, 2, 6 lines need to be swapped. Otherwise, it will cause network impassability. (2) Check the hub or

the failure of the End-to-end connectivity is not affected, so the common multimeter can not check the cause of the failure, only through the use of dedicatedThe cable tester can be checked out. The Cable is also frequently faulted during its layout, such as optical cable too long caused by the signal attenuation problem, bending transition caused by excessive optical cable bending loss and compression loss, optical cable compression or fracture, o

Motherboard failure does not boot how to do Computer boot motherboard does not start, no display, no alarm sound failure of many reasons, mainly have the following several. Treatment: For the following reasons, exclude each. (1) CPU problems CPU does not have power: Use the multimeter to test the three (or one) field tube around the CPU and three (or one) rectifier diode, check the CPU is damaged. CPU socket has a shortage of needles

packages, it is often possible to see the spring piece and control circuit board corresponding parts have dust. With absorbent cotton dipped in anhydrous alcohol cleaning, the deformation of the spring plate shape, and remove the oxide layer, under normal conditions can be restored. If the above processing is invalid, you must open the hard drive body. Choose a dust-less environment, unscrew the front cover of the hard drive screws (some with glue-bonded). When you remove the front cover of th

variety of IT services. First check if the contact is good. Can check the video card and monitor the contact between the good, the video card and the motherboard I/O slot is good contact, if necessary, it can be removed, reinstall once, ensure that the installation in place, contact good. If the contact is not a problem, it is best to change a monitor to try it to make sure the monitor is not a problem. If the monitor is not a problem, see if the CPU fan is running, such as running, using a

then check 5V voltage is normal, because the A/D driver Board MCU chip operating voltage is 5V. 2, if the search is not open the machine failure, first use a multimeter to measure 5V voltage, if there is no 5V voltage or 5V voltage becomes very low, then one may be the power supply circuit input level problems, that is, 12V to the 5V power supply part of the problem, this fault is very common, check 5-terminal voltage regulator block. 3, another ma

The keyboard is used all the time, I don't know why suddenly when I enter a character on the keyboard, I see another character on the screen. For example, the input is "F", which shows a true "J". This problem may be due to a short-circuit phenomenon on the circuit board, the main manifestation of this problem is to press a key to display the same column of other characters. At this point, the user can use a multimeter or wave device to measur

, after discharge, the system will automatically shut down. (6) Because at this time the battery temperature is high, should not be turned on immediately, let the battery cool for a while, plug in AC power. (7) Boot the computer with a floppy disk, the file will automatically run the Refresh program, and ask the user whether to proceed. (8) At this time, the refresh program began to refresh the battery, the process is very fast, when back to the DOS prompt a:>, indicates that the refresh has

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 re

stage is the expert system stage. Network analysis software by grasping the data packet, according to its characteristics and the relationship between the time stamp, to determine the network data flow is no problem, which layer of the problem, how serious. The expert system is not only limited to decoding, but also helps the maintenance personnel to analyze the network fault, the expert system will give the suggestion and the solution. The third stage is to develop network analysis tools into

, capacitance pins are colliding, whether the surface is burnt, the chip surface is cracked, the motherboard on whether the copper foil burning. Also want to see if there is a foreign matter falling into the motherboard components. Where there is doubt, you can use the multimeter to measure. Touch some of the chip's surface, if abnormal hair hot, can change a chip to try. 3, Resistance, voltage measurement method: In order to prevent accidents, should

, for the male to be able to use the PIN definition, the parent can be understood as the pin definition she is going to receive. For example, the female 2 foot is understood as she wants to connect to the receiving data side of the male header. The following is an internal structure diagram of MAX232:Assuming the male head, the connection method is: MAX232 (14,7) connecting the male (3),MAX232 (13,8) connecting the male (2). assuming the female head, the connection method is: MAX232 (14,7) conne

disk boot entry in the BIOS. Computer Black screen Solution analysis: For the computer black screen processing is basically the elimination, replacement of the combination of methods, the principle should be in line with the first to replace the most suspicious parts. For ordinary computer users, the lack of expertise, you can follow the following steps to analyze the cause of the failure, so that you can do their own troubleshooting. First check whether the contact is good. You can check th

position. Attached: Hard drive motor drive chip resistance measurement method Hard disk motor drive chip is the most vulnerable part of the hard drive circuit chip, about 70% of the hard drive circuit failure is caused by the chip damage. and whether the motor-driven chip in the end can be damaged by the chip around the pin to the ground resistance to the approximate judgment. The following table is a common hard disk motor drive chip each PIN to the ground reverse resistance table. Used to c

be pin-defined, the female can be understood to be the pin definition she wants to receive. For example the female head 2 feet understand as she wants to connect the header to the receiving data end.The following is an internal structure diagram of MAX232:If using male, the connection method is: MAX232 (14,7) connection male (3), MAX232 (13,8) connection male (2).If the female header is used, the connection method is: MAX232 (14,7) connection female (2), MAX232 (13,,8) connection male (3).We us

connection, the sending end of the connection. so, for the male to be able to use the PIN definition, the parent can be understood as the pin definition she is going to receive. For example, the female 2 foot is understood as she wants to connect to the receiving data side of the male header. The following is an internal structure diagram of MAX232:Assuming the male head, the connection method is: MAX232 (14,7) connecting the male (3),MAX232 (13,8) connecting the male (2). assuming the female h