Nguyen Computer

I have dozens of computer units, from the beginning of 586, and now dual-core machine, the time span, model, with some Shiyong longer the computer, in addition to the software’s problems, the hardware also began to occur because of aging, etc. fault, which has been repaired, while the author combined with other electronic equipment repair experience, the experience accumulated experience of sharing with you.

Foreword: Board is responsible for the bridge to connect computer components, the stability of their work directly affects the computer can function properly, due to its integration of multiple and complex components and circuits, resulting in relatively more reasons for failure, motherboard failure the performance of the system often failed to start, no display screen is difficult to visually determine the failure phenomenon. The following are summary of several maintenance methods, advantages and limitations of both the hope of giving top priority to combine.

1, cleaning method that is most commonly used one kind of approach is often the most efficient and simpler, on Shiyong more than 3 years work environment Preferred bad machine, open the Zhuji later, brush gently brush Qu board Shang’s dust brush to prevent static electricity, dust absorption with chemical testing instrument ball blown the best ear, usually with a hair dryer machine cleaning. Second, use of pins on the motherboard of some form of expansion cards, chips, sometimes because of poor contact pin-oxidation, is more obvious in summer when wet. After removal of the surface oxide layer with the eraser to re-plug, the general failure are excluded.

2, observation is the most intuitive way of a check, look carefully at the board to be revised, preferably high intensity work light, observe the plug, the outlet is skew, resistance, capacitance pin is bumped, with or without burning the surface coke, chips existence of surface cracking, discoloration and other abnormal copper foil on the motherboard or without tilt, burns out. Would also like to see if a foreign body between the components fall into the motherboard. Encounter areas of doubt, with a multimeter weigh. At this time also can be turned off, immediately repair, a number of chips with your fingers touch the surface, feeling hot with or without abnormal phenomena in general and even if the chip hot heat, the performance is already damaged.

Maintenance instance: chassis, normal maintenance and dismantling after accidentally fall into the category of small screws conductive material, the card’s components on the motherboard causing a short circuit between, rise to a “failure.” The other is the number of compatible at the assembly, motherboard and chassis, between the small installed base plate for supporting motherboard pillars, the leading motherboard installed improperly, motherboard and chassis, chassis deformation Ershi shorted to short-circuit protection with automatic power cut off power.

3, the menu law rang the method, regularity, and can be directly prescribe the right medicine, often Shoudaobingchu. Maintenance Examples: When faced with the following general phenomenon, the computer can not correctly find the hard disk boot; boot after the system time is incorrect; CMOS settings can not save the phenomena, first check the motherboard clear CMOS jumper is set to “CLEAR” option (generally 2-3) or “NORMAL” option (usually 1-2), and then re-set (which usually skip to step no one to touch the motherboard itself will not change the jumpers). Non-CMOS jumper error, 99% of motherboard battery damage or battery-voltage caused by the exchange board button battery exclusion (battery life about 5 years).

4, resistance, voltage measurement test computer motherboards, and other appliances, like principles, such as short circuit is suspected, it is necessary before the measurement in the power-board +5 V power supply and ground (GND) between the resistance value. Chip can also be measured directly between the power supply pin and ground resistance. Typically about 300Ω resistor should not be less than 100Ω. Reverse resistance, slightly different, but not too much difference. Positive and negative or close to the conduction resistance is small, indicating a short circuit there certainly needs to pinpoint the cause. Will have several causes such phenomena:

(1) on the system board has been breakdown of the chip, can be used for simple observation ruled out, could not find the use of narrowing the scope of investigation and classification off, (no power, can only detect short-circuit chip part).
(2) damage resistance and capacitance, resistance short circuit, capacitor breakdown (which can see changes in appearance).
(3) there are conductive debris (mainly, dust, etc.), or the joints between the short (less likely).

5, plug-exchange process in the maintenance of this approach is a shortcut, the premise is the same model at hand has a good motherboard, you can use the method of measurement of electrical resistance measurement board of doubt, by contrast, can quickly find chip failures. However, this method is more complicated, and the risk of risking damage to a good motherboard, and the exchange of many devices for welding parts (motherboard itself is a whole, only a few chips can plug), means a higher degree of difficulty, this stage is recommended return to factory repair.

6 of hardware and software diagnostics
Software fault in the motherboard is also certain percentage, as motherboard driver lost, damaged, repeat the installation, causing the operating system to guide the work of the operating system failure or instability caused by the fault, and then click open “Control Panel – System – Device Manager” check “system devices” in the project, if a yellow exclamation mark, question mark. Yellow exclamation point or question mark will be playing all the items to delete or uninstall (in “safe mode” to operate), re-install the motherboard comes with the drive, restart can be restored.

Hardware detection: a randomized diagnostic procedures, special maintenance diagnosis cards and under the technical parameters (such as the interface to address), special diagnostic procedures to aid in hardware maintenance, to achieve maximum results. CPU, and based on the assumption that bus operating normally, to run the diagnostic software that can run the installation on the I / O bus slots on the diagnosis of cards. The principle is program testing software to send data, commands, and by reading the line status and a chip (such as registers) state to identify the fault location is suitable for checking all kinds of faults and has the address of the interface circuit various circuit parameters.

7, after briefly complex together to form the main principles of Judgement PC motherboards are used in large scale integrated circuits, and control logic integrated more and more, by measuring its logic is difficult to judge the correctness. Must first determine simple logic chips and resistance Yung Yuan Jian, and then focus on the logical relationship between the fault difficult to judge the LSI chip, to provide reference for the further maintenance, the author limited to repair chips Deng Tiaojian restrictions, no such practice.

Conclusion: Motherboard troubleshooting methods, the most important reason is based on failure to come there, such as the general 4 years motherboard failure, failure of the normal application of probability, almost all of CPU heat near the filter capacitor, the electrolyte dry reduced capacity caused by frequent crashes, etc., direct observation was found by violent plasma leakage phenomenon, (I have repaired many times) again, if the true chip-level maintenance, motherboards and different from the hard drive and other storage devices, their added value high value is not so high maintenance, and generally getting lower and lower prices of new products, increasing performance, can be directly resolved by replacing the new motherboard, as the ultimate repair tool.