If there is parasitic oscillation phenomenon in the circuit, a capacitor with a certain capacity can be used to cross connect the capacitor between the place to be inspected or the reference ground point, and then observe whether the oscillation exists. If the oscillation disappears, it indicates that the oscillation is generated in the previous circuit or nearby circuit. If not, move back and continue searching for checkpoints. The selection of capacitors should pay attention to the bypass capacitance not being too large, as it can effectively eliminate unfavorable signals. The use of the open circuit method for short circuit checking is also the most effective. The thinking of the circuit breaker inspection method is similar to the previous methods, which are used to eliminate suspicious points and shorten the scope. Assuming that the regulated power supply is connected to a faulty circuit and the output circuit is too large, then if we sequentially disconnect a certain part of the circuit's branches and observe the current output of the circuit, we can determine the faulty branch