1. Fault phenomenon: no display when the fluid is flowing normally, the total counter number does not increase
2. Possible reasons
a .Check the power cord, fuse, function selector switch, and signal cable for open or poor contact
b. Check the internal printing plate of the display, contact parts, etc. for poor contact
c .Check the detection coil
d. Check the internal fault of the sensor. All the above 1-3 checks confirm that the fault is normal or has been eliminated, but there is still a fault phenomenon, indicating that the fault is inside the sensor flow channel. You can check whether the impeller touches the inner wall of the sensor, whether there is any foreign matter stuck, the shaft and Bearings have no debris stuck or broken
a. Use an ohmmeter to troubleshoot the point of failure
b. Printing board failure check can be replaced by the "alternate version" method, replace the fault board and then carefully check
c. Do the position mark of the detection coil on the sensor body, unscrew the detection head, and use the iron piece to move quickly under the detection head. If the number of counters does not increase, check the coil for disconnection and solder joint de-soldering.
d. Remove foreign matter, and clean or replace the damaged parts. After recovery, blow the air or hand the impeller. There should be no friction. After replacing the bearings and other parts, re-verify and obtain a new meter factor.