First of all, from practical experience, the resistance is not easy to fail, when the resistance is bad, most of the black marks can be seen from the appearance, or cracks. After the resistance is disconnected from the system (disconnect one of the feet), the ohm file of the meter can be used to measure the resistance value and confirm its quality. To measure the capacitor, it is also necessary to disconnect the capacitor from the system (disconnect one of the feet), the premise is that the selected meter needs to support the measurement function of the capacitance value, otherwise it will not be able to measure the small-capacity capacitor. Large capacitance capacitors, you can use the ohm file of the meter to charge the capacitor first, and then quickly reverse the red and black watch pen to roughly determine whether the charge and discharge characteristics of the large capacitor are normal. IC and MOSFET also need to be disconnected from the system, using the Diode gear on the meter, measure the value of the internal Diode of the IC (both through the circuit and the reverse cut-off) in addition to VDD\/VSS other pins, most ics will have two equivalent diodes (except some specially designed ics) As ESD protection. 1. From this pin to VDD, 2. From VSS to this pin, determine the VDD \/VSS position on the package pin and then compare the specifications to determine the corresponding IC model. The above hope can help you.