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In a vortex flowmeter, there is flow in the pipeline but no output from the flow meter. The possible causes of this fault and the corresponding solutions are as follows: (1) A possible cause of the fault is an issue with the power supply or the fact that the power supply is not connected. Therefore, it is necessary to check whether the supply voltage meets the requirements and whether the power polarity is correct. In current-output type vortex flowmeters, if the power supply polarity is reversed, the output current will be 0 mA instead of 4 mA. (2) Possible causes of the fault are a broken connection cable or incorrect wiring. It is necessary to check whether the circuit is unobstructed; if there is a fault, rewire it and check again. (3) A possible cause of the failure is that the ripple factor of the power supply is too high. A filtered electrolytic capacitor can be used for testing during inspection; generally, a capacitor with a capacity of 3100 μF and a voltage rating of 50V is required. (4) A possible cause of the failure is a malfunction in one of the amplification stages of the vortex flowmeter. It is possible to observe the waveforms at the input and output terminals of the amplifier, or to inject a human-body detection signal at the input terminal and watch for changes at the output terminal. If there is no change at the output, it indicates that the amplifier is not functioning properly. In actual maintenance, it is also possible to use other types of flowmeter motherboards available on site for replacement and inspection. It has been determined that the amplification plate is faulty and should be replaced. (5) A possible cause of the failure is damage to the sensor element of the vortex flowmeter. The testing method involves first increasing the flow rate and replacing this vortex street main board with a vortex street flow meter of the same type; if the main board is not at fault, then the generating element is inspected. Damage to the vortex generator in vortex flowmeters often occurs in steam measurement systems; this happens when process operators open valves too quickly, causing high-temperature, high-pressure steam to carry condensed water with it, which then strikes the vortex generator with force and leads to its damage – a phenomenon commonly known as \"water hammer\". Therefore, the drain valve should be opened to discharge the condensate water first, and then the steam valve should be opened slowly to avoid damaging the vortex generator. (6) A possible cause of the failure is that the pipeline flow rate is too low, falling outside the measurement range. The flow rate can be increased to observe the meter’s response. By tapping regularly and continuously on the pipe adjacent to the vortex flow meter, a flow rate reading will be displayed for any type of vortex flow meter. If the medium under test is a liquid, it is best to conduct a tube-free test, as the liquid itself acts as a shock absorber. The method for dealing with this issue is to replace the flow meter with one having a smaller diameter, or to increase the flow rate if the process conditions permit it. (7) A possible cause of the failure is whether the gap between the body and the housing is blocked by fine particles. This phenomenon generally occurs after normal operation, when the machine is shut down and then restarted. If that is the case, and it is confirmed that both the conversion amplifier and the generator are intact, especially when the measuring medium is a liquid, this can generally be considered to be that type of fault. The approach is to increase the flow rate as much as possible if the production process conditions permit, and to strike vertically on the weld pad at the bottom of the flow meter using a wooden or rubber mallet, so that the negative pressure generated by the high-speed fluid can carry away the fine solid particles. If disassembly and cleaning are permitted on site, the flow meter unit can be removed, but it is necessary to be familiar with its structure, especially the gaskets and screw bolts used for securing components; installation must be carried out strictly in accordance with the instructions provided. It should also be noted that reinstalling the component after disassembly may cause some changes in the flow coefficient; although these changes are not significant, they still need to be corrected. (8) Check the parameter settings according to the vortex flowmeter manual to ensure there are no errors; if any, make the necessary corrections.