With the rapid development of economy and science and technology in recent years, the computer hardware industry is gradually enriched and more optimized, and gradually loved by thousands of families. However, the operation of the computer must involve the participation of the main board. In the use of the industrial control motherboard, the industrial control motherboard will fail for various reasons. At this time, it is necessary to overhaul the industrial control motherboard to accurately find out the problem of the industrial control motherboard. What are the common maintenance methods of industrial control motherboard? Today, Zhun Qin will learn five maintenance skills of industrial control motherboard with you:

1、 Program test method: this method is mainly used to check whether various interface circuits and circuits with address parameters have faults. Its principle is to send data and commands with software and identify the fault location by reading the line status and the status of a chip (such as register).

2、 Check whether there is a short circuit on the industrial control motherboard: before power on, measure whether there is a short circuit on the industrial control motherboard to avoid accidents. The judgment method is: measure the resistance between the power pin of the chip and the ground. When the power plug is not inserted, the resistance shall generally be 300 Ω, and the minimum resistance shall not be less than 100 Ω. Measure the reverse resistance value again. There is a slight difference, but the difference cannot be too large. If the forward and reverse resistance is very small or close to conduction, it indicates that there is a short circuit on the industrial control motherboard. The reason for the short circuit of the industrial control motherboard may be that there are damaged resistors and capacitors or conductive sundries on the industrial control motherboard, or there may be a broken chip on the industrial control motherboard. To find the punctured chip, you can plug in the power supply and power up the measurement. Generally, measure the + 5V and + 12V of the power supply. When it is found that a certain voltage value deviates too far from the standard, the voltage can be measured again by separation method, cutting some leads, or unplugging some chips. When a lead is cut or a chip is unplugged, if the voltage becomes normal, the component led out by this lead or the chip unplugged is the fault.

3、 Dust removal method: the industrial control motherboard has a large area and is a place where more dust is accumulated. Dust can easily lead to poor contact between the slot and the board. In addition, some cards and chips on the industrial control motherboard use pin forms, and often have poor contact due to pin oxidation. It is recommended to gently brush the dust on the industrial control motherboard with a wool brush. Be careful not to use too much force or act too hard, so as not to touch the patch components on the surface of the industrial control motherboard or cause looseness of components, resulting in false welding. Pay attention to remove the dust on the thermistor used to detect the CPU temperature in the CPU slot or on the industrial control motherboard to monitor the temperature in the chassis, otherwise the industrial control motherboard will identify the temperature incorrectly, resulting in the protective failure of the industrial control motherboard. If the poor contact is caused by the oxidation of the slot pin, fold the hard white paper (the smooth surface faces outward), insert it into the slot and wipe it back and forth; For card pins, remove the surface oxide layer with an eraser, and then plug them again.

4、 Unplugging and switching method: first shut down, and then pull out the plug-in board one by one; Every time a board is pulled out, start the machine and observe the running state of the machine. Once a board is pulled out and the industrial control motherboard runs normally, it is that the plug-in board is faulty or the corresponding I / O bus slot and load circuit are faulty; If the system starts abnormally after pulling out all plug-in boards, the fault is likely to be on the industrial control motherboard.

5、 Static / dynamic measurement method:

1. Static measurement method: pause the industrial control motherboard in a close-up state, measure the level of relevant points with a multimeter or logic pen according to the circuit logic principle or the logical relationship between chip output and input, and analyze and judge the cause of the fault.

2. Dynamic measurement and analysis method: prepare special judgment program or artificially set normal conditions. During the operation of the machine, measure and observe the waveform of relevant components with oscilloscope and compare it with the normal waveform, so as to judge the fault position.

The above are the five common maintenance skills of industrial control motherboard shared by Zhun Qin. I hope you can correspond to various maintenance skills and solve the problems faster and more conveniently when facing the situation of industrial control motherboard.