2022-02-25
To repair a relatively unfamiliar circuit board of an injection molding machine without any principle, the so-called "experience" in the past is difficult to make a difference. Although people with strong hardware skills are full of confidence in maintenance, if the method is not appropriate, it will still work with half the effort. . So, what can be done to improve maintenance efficiency?
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 inspect it visually, and if necessary, use a magnifying glass to see what?
Mainly see:
1. Is there 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 circuit board on the circuit board of the injection molding machine;
4. Has anyone repaired it? Which components have been moved? Whether there are any mistakes in operation such as virtual welding, missing welding, reverse insertion, etc. 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, It is only a few or a dozen ohms, indicating that there are components on the circuit board of the injection molding machine that are broken down or partially broken down, and 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, triodes, field effect transistors, and dial switches on the board. The purpose is to first ensure that the measured components are normal. Our reason is that we can use Don't complicate the problem solved by the multimeter.
Method 2: First outside and then inside
Tools used: circuit online maintenance instrument
If the situation allows, it is best 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 together to perform a good and bad comparison test on the two boards. The initial comparison point can start from the port , and then from the outside to the inside, especially the comparison test of the capacitance, can make up for the lack of multimeter online detection of leakage.