Even if I have been repairing hydraulic injection moldi […]
Even if I have been repairing hydraulic injection molding machines for many years and I am quite confident in maintenance technology, using the experience of repairing hydraulic injection molding machines in the past to repair all-electric injection molding machines will feel powerless when working. So, what can be done to repair the all-electric injection molding machine? Based on maintenance experience, the following steps should be followed in an orderly manner.
1. Whether there is disconnection; 2. Whether there is scorching phenomenon, such as resistance, electrolytic capacitor bulging, inductance, second tube, third tube, IC have obvious burn marks; 3. Whether there is water and oil. Most of the circuit boards of the all-electric injection molding machine are digital circuits, which are very sensitive to resistance. If the resistance of the circuit is changed by water and oil, logic errors will occur; 4. Whether anyone has repaired or damaged it, Whether there are operational errors such as virtual welding, reverse insertion, copper foil disconnection, missing welding, etc; 5. Whether some components have high temperature phenomenon. Pay special attention to the power supply, large power components, and ICs.
If you can find a good circuit board that is the same as the circuit board to be repaired as a reference, then you can use a multimeter, oscilloscope and other tools to compare the good and bad of the two boards. You can compare the I/O voltage and resistance of the circuit board, and if you have an oscilloscope, you can also compare the waveform frequency.
When a problem is detected, or the scope of the fault has been reduced to a certain area, but the point cannot be determined, we can use the substitution method to find the faulty component.
1. When the power supply is short-circuited and you don't know which component it is, you can connect an adjustable power supply and modulate the voltage to 50% of the normal power supply. When looking at the IC or component, the temperature is obviously high. This is generally the problem with this component.
2. Some components on the circuit board may not find the same, so check the relevant information to see if this component is replaced. If not, analyze the working function of this component. For example, a three-state transceiver, since most of these components work in parallel, the bad ones can be removed. General circuit boards can be used, but some functions will fail. But this can find the problem.
During the online test or comparison of the device, if the test passed (or relatively normal) device, please directly confirm the test result, so as to record the failure (or relatively poor), you can test again, if it still fails, also You can confirm the test results first, and continue testing like this until the devices on the board are tested (or compared), and then go back and deal with those devices that have not passed the test (or are relatively poor).
For devices that fail the functional online test, the instrument also provides a less but more practical processing method. Since 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 pin of the device through the test clip, if the power supply 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. The device undergoes online function testing. Since other devices on the circuit board of the injection molding machine will no longer interfere, the actual test effect is equivalent to "quasi-offline", and the accuracy rate will be great.
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 comparative test of the device, as long as the test clamp can clamp the device, and a reference board, through the comparison test, the device also has a strong fault detection capability.
This function makes up for the insufficiency of the machine's online function test subject to the test library, and expands the instrument's detection range of injection molding machine circuit board failures. In reality, there are often scenarios where a good board cannot be found as a reference, and the circuit structure of the board to be repaired is also not symmetrical.
In this case, the ASA-VI curve scanning comparison test function does not work, and the online function test cannot be completed for every period on the injection molding machine circuit board due to the lack of the period test library, and the injection molding machine circuit board is still It cannot be repaired. This is the limitation of the online circuit repairer, just like there is no newspaper.