The multimeter can't check the line.
The digital multimeter buzzer can be used to test the conduction of wires. The two probes touch the two ends of the wire respectively. If you hear a "beep" sound, the wire is on, and there is no sound indicating that the wire is off. Please refer to the following steps to confirm.
1. Find a digital multimeter, insert the red probe into the "voltage/resistance/diode/on-off buzzer measuring terminal" interface of the multimeter, and insert the black probe into the "common measuring terminal" interface.
2. Press the power button (that is, the power button) of the multimeter to start the machine, and press the Hold button to check the switching and holding function of this key. Then turn the big knob in the middle of the multimeter to test whether the function conversion is normal.
3. After confirmation, adjust the position of the large knob to the buzzer diode gear.
4. Touch the red pen with the black pen. If it is a buzzer, you can hear the buzzer. If you don't hear the buzzer, check whether the stylus is plugged in or damaged. If the check is not a stylus problem, it means that it is in the "diode gear" at this time. Press the hold key to switch the function to the "buzzer gear".
5. Then touch the red probe and the black probe of the multimeter with both ends of the wire respectively. If you hear the buzzer, you can judge that the wire is conductive, otherwise it will not work.
What gear does the multimeter use to check whether the line can't get through, and the number is normal.
When measuring whether the line is connected or disconnected with a multimeter, it is necessary to select the gear according to what line is being measured. For example, to measure whether the line is blocked when lighting is not on, you can check whether the power supply is normal with a voltage file above 250V V. If the voltage indicator of the power supply for turning on or off the lighting switch remains unchanged, it is certain that there is something wrong with the lighting line or the light bulb. If the voltage changes, you can judge that the power supply line is faulty. If it is simple to measure whether a section of wire is broken in the middle, you can use the position switch in the figure to turn the second gear counterclockwise, that is, the measuring diode and the "on-off" gear, which is a special gear for measuring the on-off of general power supply wires and the quality of diodes with a digital multimeter. When the resistance between the measuring probes of this gear is very small (generally less than 200Ω or measuring the forward resistance of diodes), it will directly give a continuous sound prompt. If the resistance between the probes is large (there is a break or the diode is in reverse connection), no sound will be generated. If there is intermittent sound in the shaking line during measurement, it means that there is poor contact in the shaking part and the line will be broken. Pay attention to using resistance to measure the gear position, and the power supply should be disconnected.
