Analysis of Common Failures in Electronic Truck Scales, hoping to be helpful to everyone.

1. Unresponsive buttons: First, replace with new buttons for testing. If the new buttons function normally, it can be determined that the original buttons have poor contact. Check if there is an open circuit or cold solder joint in the line between the buttons and the CPU. Inspect if the button holder has poor contact.

2. Garbled display: Remove the original display circuit and replace it with a normal one to see if it works properly. If the display is normal, it indicates a problem with the original display circuit. If not, check if the drive circuit is faulty, and finally check if the output pins of the processor's display output are within a reasonable output range.

3. Failure to power on: First, confirm that the issue is not caused by the fuse, power switch, power cord, or voltage switch. Check if the transformer has AC voltage input and output. If the meter is equipped with a battery, remove the battery and power it on with AC power to see if it is caused by insufficient battery voltage. Then, check if the rectifier circuit, voltage stabilizing circuit, and display drive circuit are abnormal. If all these are normal, check if the processor and its auxiliary circuits are burned out.

4. Failure to return to zero: Check if the sensor output signal value is within the standard range (A/D total amplification code/used internal code range/base code range). If the signal value is not within the standard range, adjust the sensor's adjustable resistor to bring the signal value into the standard range. If compensation is not possible, check if the sensor is faulty. With the sensor output normal (stable scale body), confirm the meter fault, which is generally a problem with the amplifier circuit and A/D conversion circuit. Then, test and analyze one by one according to the circuit principle to finally solve the problem.

5. Failure to reach full load capacity: Similar to the situation of failure to return to zero, it is mostly due to a change in the signal input range. Test according to the method for failure to return to zero. If no problem is found, first check if the power supply and A/D circuit are normal, then check the sensor output.

6. Inaccurate weighing: Observe if the internal code value is stable, if there is friction in various parts of the sensor, if the regulated power supply is stable, if the operational amplifier circuit is normal, and use weights to test if the weighing at the four corners of the truck scale is balanced. Follow the instructions in the manual to further conduct partial analysis of the meter or weight calibration.