Maintenance Techniques for Injection Molding Machine Computer Board

Method 1: First look and then measure
Tools used: multimeter, magnifying glass
When holding a circuit board for an injection molding machine to be repaired, a good habit is to first visually inspect it, and if necessary, use a magnifying glass to see what?
Mainly looking at:
1. Is there any wire breakage;
2. Discrete components such as resistance, electrolytic capacitor, inductance, diode, triode, etc. are disconnected;
3. Check if the printed circuit board connecting wires on the injection molding machine circuit board are broken, adhered, etc;
4. Has anyone repaired it? Which components have been touched? Whether there are errors in operation such as false soldering, missing soldering, and reverse insertion; After confirming that the repaired part does not have the above conditions, first use a multimeter to measure the resistance value between the power supply and ground of the injection molding machine circuit board. If the resistance value is too small, only a few or more ohms, it indicates that there are components on the injection molding machine circuit board that have been broken or partially broken, and measures must be taken to find the broken components. The specific method is to supply power to the repaired circuit board and touch the temperature of various components on the injection molding machine circuit board with your hand. Those who are hot will be the key suspects. If the resistance value is normal, use a multimeter to measure the resistance, diode, transistor, field-effect transistor, dial switch, and other vertical components on the board. The purpose is to first ensure that the measured components are normal. Our reason is that the problem that can be solved with a multimeter should not be complicated. String 1
Method 2: First outside then inside
Tool used: Circuit online maintenance instrument
If the situation allows, it is best to find a good board that is the same as the repaired board as a reference, and then use the dual bar VI curve scanning function together to compare the good and bad of the two boards. The starting point of comparison can be from the port, and then from the outside to the inside, especially for the comparison test of capacitance, which can make up for the shortcomings of the multimeter's difficulty in measuring whether there is leakage online.
Method 3: Easy first, then difficult
Tools used: circuit online maintenance instrument, electric soldering iron, marking pen
To improve the testing effect, before conducting online functional testing on the circuit board of the injection molding machine, some technical treatment should be carried out on the repaired board to minimize the negative impact of various interferences on the testing process. The specific measures are:
1. Before the test, prepare to short-circuit the crystal oscillator. Solder the next leg of the large electrolytic capacitor to open it, because the charging and discharging of the capacitor can also cause interference.
2. During the online testing or comparison of devices using the exclusion method, for devices that pass (or are relatively normal) the test, please directly confirm the test results for easy recording; For devices that fail the test (or are out of tolerance), they can be retested again. If they still fail, the test results can be confirmed first, and the test will continue until the devices on the board are tested (or compared). Then, we will return to dealing with those devices that fail the test (or are out of tolerance). For devices that have not passed the online functional testing, the instrument also provides an informal but practical processing method. As the power supply to the injection molding machine circuit board can be applied to the corresponding power and ground pins of the device through a test clamp, if the power pins of the device are cut, the device will detach from the injection molding machine circuit board power supply system. At this time, the device will undergo online functional testing, Due to the fact that other components on the circuit board of the injection molding machine will no longer interfere, the actual testing effect is equivalent to "quasi offline", and the accuracy rate will be greatly improved.
String 1
3. Comparative testing of devices not yet covered by the testing library using ASA-VI curve scanning testing
Due to the fact that ASA-VI intelligent curve scanning technology can be applied to comparative testing of any device, as long as the test clamp can clamp the device and there is a reference board, through comparative testing, it also has strong fault detection ability for the device. This function compensates for the limitation of online functional testing of devices being limited by test libraries, and expands the detection range of the instrument for circuit board faults in injection molding machines. In reality, there are often situations where a good board cannot be found as a reference, and the circuit structure of the board to be repaired does not have any symmetry. In this case, the ASA-VI curve scanning comparison testing function cannot work, while online functional testing cannot complete testing every component on the injection molding machine circuit board due to the incomplete device testing library. The injection molding machine circuit board still cannot be repaired, Here are the limitations of online circuit maintenance equipment, just like there is no cure for all diseases.
Method 4: Quiet before moving
Due to the fact that the online circuit maintenance instrument can only perform functional online testing and static feature analysis on the components on the circuit board of the injection molding machine, it is necessary to undergo a complete machine testing inspection to ensure complete repair. Therefore, it is best to first check whether the power supply of the equipment is correctly supplied to the injection molding machine circuit board as required during the inspection.