This is how you can measure the quality of the capacitance with a multimeter
There are two ways to detect the quality of a capacitor: one is to judge the quality of the capacitor by its appearance; the second is to use a multimeter to measure whether the capacitor is damaged.
Whether it is an electrolytic capacitor or other non-polar capacitor, if there is obvious swelling and swelling, it can basically be concluded that the capacitor is no longer usable. This is a way to judge the quality of the capacitor by its appearance.
It is very accurate to use a multimeter to detect whether the capacitor is damaged. Taking the analog multimeter as an example, we will introduce the method of measuring capacitance. If the capacitance to be measured is an electrolytic capacitor with a capacity of less than 10uf, you can use the multimeter's resistance setting R×1K to measure it; if the measured capacitance is tens of microfarads or hundreds of microfarads, the corresponding resistance setting of the multimeter must be Dial to the R×100 ohm range or the R×10 ohm range for measurement. The greater the capacitance, the smaller the range of the resistance range used by the multimeter to achieve measurement accuracy. Those small stepless ceramic capacitors have very small capacity. The multimeter should be set to R×10K to detect slight jitter.
Let's talk about the measurement method. Completely separate the capacitor to be measured from the circuit board, set the multimeter to the corresponding resistance position, and connect the two needles to the two legs of the capacitor. Four situations will occur: the needles deflect to a certain It slowly returns to the zero position, indicating that the capacitor is good; the needle is motionless, indicating that the capacitor is damaged by an internal circuit break; the needle deflects to the zero position and does not return, indicating that the capacitor has been seriously short-circuited and damaged and cannot be used; the needle deflects to a certain position and is fixed. If it remains unchanged, it means that the capacitor has leakage. If the leakage is serious, it cannot be used. Non-polar small capacitors can only be measured in the 10K range. The needle should shake slightly, which means it is good. If the needle does not move or deflect to zero, it means it is damaged and cannot be used.
