Troubleshooting experience of injection molding machine
To repair a relatively unfamiliar circuit board of an injection molding machine without any schematics Do more with less. So, what can be done to improve maintenance efficiency? According to SUDA's long-term failure repair experience of injection molding machines, it is concluded that the following steps should be followed and carried out in an orderly manner.
Method 1: Look first and then measure
Tools used: multimeter, magnifying glass, when holding a circuit board of an injection molding machine to be repaired, it is a good habit to first check it visually, and use a magnifying glass if necessary, what to look at?
Mainly see:
1. Whether there is a disconnection;
2. Disconnection of discrete components such as resistors, electrolytic capacitors, inductors, diodes, triodes, etc.;
3. Whether there is any breakage, adhesion, etc. on the printed board connection line on the circuit board of the injection molding machine;
4. Has anyone repaired it? Which components have been moved? Whether there are operational mistakes such as virtual welding, missing welding, and reverse insertion;
After confirming that the repaired parts do not have the above conditions, first measure the resistance between the power supply and the ground of the circuit board of the injection molding machine with a multimeter. If the resistance is too small, only a few or a dozen ohms, indicating that there is a If the components are broken down or partially broken down, measures must be taken to find the broken down components. The specific method is to supply power to the circuit board to be repaired, and touch the temperature of each component on the circuit board of the injection molding machine with your hands. Those who are hot will be the key suspects. If the resistance value is normal, use a multimeter to measure discrete components such as resistors, diodes, transistors, FETs, and DIP switches on the board. The purpose is to first ensure that the measured components are normal. Our reason is that we can use a multimeter Solve the problem, don't complicate it.
Method 2: First outside and then inside
Tools used: circuit online maintenance instrument
If the situation allows, it is better to find a good board that is the same as the board to be repaired as a reference, and then use the dual-rod VI curve scanning function to perform a good and bad comparison test on the two boards. The initial comparison point can start from the port, Then from the outside to the inside, especially the comparative test of the capacitance, it can make up for the shortcoming that the multimeter is difficult to detect whether there is leakage online.
Method 3: Easy first and then difficult
Tools used: circuit online repair instrument, electric soldering iron, marker pen
In order to improve the test effect, before the online functional test of the circuit board of the injection molding machine, some technical treatment should be done on the repaired board to minimize the negative impact of various disturbances on the test process. The specific measures are:
1. Preparation before the test
Short-circuit the crystal oscillator, and solder a foot to the large electrolytic capacitor to make it open, because the charging and discharging of the capacitor can also cause interference.
2. Use the exclusion method to test the device
During the online test or comparison of the device, for any device that passes the test (or is relatively normal), please directly confirm the test result for recording; if the test fails (or is out of tolerance), you can test it again. Pass, you can also confirm the test results first, and keep testing like this until the devices on the board are tested (or compared), and then go back to deal with those devices that fail the test (or are out of tolerance). For devices that fail the functional online test, the instrument also provides a less formal but more practical processing method, because the power supply of the instrument to the circuit board of the injection molding machine can be applied to the corresponding power supply and ground of the device through the test clip. If the power pin of the device is cut, the device will be separated from the power supply system of the circuit board of the injection molding machine. At this time, the online function test of the device will be performed. Since other devices on the circuit board of the injection molding machine will no longer interfere, the actual test The effect is equivalent to "quasi-offline", and the accuracy rate will be greatly improved.
3. Use the ASA-VI curve scan test to compare and test the devices not covered by the test library
Because the ASA-VI intelligent curve scanning technology can be applied to the comparison test of any device, as long as the test clip can clamp the device, and there is a reference board, through the comparison test, it also has a strong fault detection ability for the device. This function makes up for the deficiency that the online functional test of the device is subject to the test library, and expands the detection range of the instrument to the failure of the circuit board of the injection molding machine. In reality, it is often impossible to find a good board for reference, and the circuit structure of the board to be repaired does not have any symmetry. In this case, the ASA-VI curve scan comparison test function does not work, and the online functional test does not work. Due to the incomplete device test library, it is impossible to test every device on the injection molding machine circuit board, and the injection molding machine circuit board still cannot be repaired. Here is the limitation of the circuit online repair instrument, just like there is no cure for all diseases. .
Method 4: Be still and then move
Since the circuit online maintenance instrument can only perform functional online test and static characteristic analysis on the components on the circuit board of the injection molding machine at present, whether it is completely repaired must be tested and inspected by the whole machine. Requires correct supply to the injection molding machine circuit board.
Correctly supplied to the circuit board of the injection molding machine.
Friends with experience in fault repair of injection molding machines
With years of experience in the high-end injection molding machine industry, SUDA has devoted itself to research, continuous innovation and transcendence, and developed the SUDA brand injection molding machine shooting table, which can be equipped with any model and can be customized according to customer requirements. There are two types of SUDA injection table: electric and hydraulic. The key components such as control system and electrical are imported from Japan, Germany, the United States and other countries. The injection is stable and the precision is high.
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Troubleshooting experience of injection molding machine
