Use a digital multimeter to measure the circuit in the suspected part. Generally, we use the diode file to measure. It is short circuited with two test leads. The multimeter will call that file. Before measuring the resistance, we will do some necessary discharge behavior, and confirm that there is no market insertion. In the case of electricity, we use a pair of dice to short-circuit some capacitors. When the capacitor discharges, it will emit sparks and sounds. Don't be afraid, then carry out our on-resistance measurement.