1. Fixed capacitor detection for small capacitors below 10pF: Due to the small capacity of fixed capacitors below 10pF, measuring with a multimeter can only qualitatively check whether there is leakage, internal short circuit, or breakdown. When measuring, a multimeter R can be used × 10k gear, use two probes to connect any two pins of the capacitor, and the resistance value should be infinite. If the measured resistance value (pointer swinging to the right) is zero, it indicates that the capacitor is damaged due to leakage or internal breakdown. 2. Test 10PF-001 μ Fixed capacitor F: Determine whether there is charging phenomenon and then determine its quality. Multimeter selection R × 1k gear. Two transistor β The values are all above 100 and the penetration current should be small. Composite tubes can be composed of silicon triodes of models such as 3DG6. The red and black probes of the multimeter are connected to the emitter e and collector c of the composite tube, respectively. Due to the amplification effect of the composite transistor, the charging and discharging process of the measured capacitor is amplified, which increases the swing of the multimeter pointer and facilitates observation. 3. It should be noted that during testing operations, especially when measuring capacitors with smaller capacities, it is necessary to repeatedly switch the tested capacitor pins to contact points A and B in order to clearly see the oscillation of the multimeter pointer. For 001 μ Fixed capacitors above F can be measured using the R value of a multimeter × Directly test the capacitor for charging process and internal short circuit or leakage at 10k gear, and estimate the capacity of the capacitor based on the amplitude of the pointer swinging to the right