Some common problems and solutions of electronic balance: There are seven problems such as analysis of the failure that the weight can not be reset to zero after removal, error code is shown in electronic balance, fault analysis of inaccurate weighing of electronic balance, failure of starting up of electronic balance, the button is not easy to use, the pointer of electronic balance is bouncing, weighing full load cannot be achieved.
1. Analysis of the failure that the weight can not be reset to zero after removal
Check whether the output signal value of the sensor is within the standard (total amplification code of A/ D / using internal code range / bottom code range). If the signal value is not within the standard, adjust the adjustable resistance of the sensor and adjust the signal value to the standard. If there is no problem, please check whether there is a problem with the sensor. If the output of the sensor is normal (the scale body is stable), the fault of the locking instrument is generally caused by the problem of the amplification circuit and the A / D conversion circuit. Finally solve the problem by judging and analyzing the test one by one according to the circuit principle.
Remove the original display circuit and replace it with a normal display circuit to see if it is normal. If the display is normal, it means that the display circuit is faulty. If it is abnormal, check whether the driver circuit is faulty, and then check whether the output pin of the processor is in a reasonable output range.
3. Fault analysis of inaccurate weighing of electronic balance
Observe whether the internal weight value is stable, whether there is friction at all parts of the sensor, whether the stabilized power supply is stable, whether the operational amplifier circuit is normal, and use the weight to test whether the weight of the four foot scale is average. According to the instructions of the manual, we have further instrument local analysis or weight correction.
4. Failure of starting up
First determine the problems caused by non fuse, power switch, power line and voltage switch, and check whether the transformer has AC voltage input and AC output. If the instrument is equipped with battery, remove the battery and turn on the AC power supply to know whether it is caused by insufficient battery voltage. Secondly, check whether the rectification circuit, voltage stabilizing circuit and display driving circuit are abnormal. If there is no problem, check whether the processor and auxiliary circuit are burnt out.
5. The button is not easy to use
First, replace the new button for testing. If the function of the new button is normal, it can be judged that the key is in poor contact. Measure whether there is open circuit or faulty welding between the button and CPU. Check whether the button support is of poor contact. Measure whether the diode and resistance on the key and CPU circuit are short circuited or open circuited.
6. The pointer of electronic balance is bouncing
When the crossbeam is supported, if the distance between the cutter point of the fulcrum knife and the knife pad is not the same, the pointer will bounce when the balance is opened. Loosen the screw in front of the left arm of the cross bracket, and then adjust the height of the small strut by hand until the pointer no longer bounces.
7. Weighing full load cannot be achieved
It is similar to the situation that it cannot be reset to zero. In most cases, it may be caused by the change of small signal input range. According to the method of the situation that it cannot be reset to zero, if no problem is found, check whether the power supply and A/ D circuit are normal, and then check the sensor output.