Electronic scales and electronic balances are digitally displayed weight measuring instruments with electronic devices. Electronic scales and electronic balances are: weighing sensors, operational amplifiers, A / D conversion integrated circuits, intelligent microcontrollers, display drivers and display circuits, keyboard circuits, multi-function interface circuits, AC / DC / charging / storage / stability The voltage circuit is composed. Therefore, the phenomenon and root causes of various faults are strange. Common fault diagnosis and simple handling methods for electronic scales and electronic balances: 1. The electronic scale does not return to zero (does not return to zero, does not weigh) a. Check if the load cell output signal value is within the standard. (A/D total enlargement code / use inner code range / bottom code range) c. If it is impossible to compensate, please check if the sensor is defective. (Please check according to the eighth item) 2. The electronic scale is said to be out of weight a. Check whether the internal code value is stable, whether there is friction in all parts of the sensor, whether the stabilized power supply is stable, whether the operational amplifier circuit is normal, whether the circuit board of the A/D circuit has foreign matter, and whether the feedback resistor/capacitor/filter capacitor is defective or Leakage. b. Check if the sensor output signal value is within the standard. c. Not within the standard, please refer to the tenth item for compensation. d. Use the weight to test whether the weighing pan has an average of four feet. (If it is not average, please refer to the ninth item for grinding scale) e. Please follow the instructions to do weight correction. 3. The electronic scale can't be turned on a. Please determine if it is caused by the problem of fuse, power switch, power cord and voltage switch. b. Check the transformer for AC110/220 input and AC18V output. c. Remove the battery and turn it on with AC power to see if it is caused by insufficient battery voltage. (To measure the battery voltage, it should be higher than 6V. Please charge if it is lower than below. If it is lower than 5.5V, please replace the battery when there is no power soon after charging.) 4. The electronic scale shows bad a. Put the normal LCD pin in hand on the maintenance scale LCD, and then turn on the power to observe whether there is the same bad condition on the normal LCD. If not, it can be judged as LCD failure. b. Check the CPU pins for oxidation, cold soldering or short circuit. c. Whether the pins and holes of the LCD are oxidized, cold welded or short-circuited. d. Check if there is any open circuit between the CPU and LCD. 5. The electronic scale button is bad a. Please update the K/B test first. If the new K/B function is normal, it can be judged as K/B. b. Measure whether the circuit between K/B and CPU is open or cold. c. Check if the K/B foot has a bad contact. d. Measure whether the K/B and the diode on the CPU circuit are short-circuited or open. 6. Electronic scales cannot be scaled to full load a. Check if the sensor output signal value is within the standard. b. Not within the standard, please refer to the tenth item for compensation. c. If it is impossible to compensate, please check if the sensor is defective. (Please follow the eighth item for testing) d. If there is instability or compensation after compensation, please replace the sensor. e. Check for interference from wireless materials or protective devices inside. f. Whether the battery voltage is above 6V. g. Replace the L/C test for poor sensor. 7. Electronic scale battery cannot store electricity a. Please make sure that it is not caused by the fuse, power switch, power cord and voltage switch. b. Check the transformer for AC110/220 input and AC18V output. c. Remove the battery from the board and take the PIN to measure whether the charging voltage of the machine is about 7.2V. If not enough, please check the power supply related circuit. d. Check the machine version, whether the diode near the input terminal of the transformer is normal. e. Replace the battery. 8. Electronic scale sensor bad judgment a. Static method: use the ohmic file of the three-meter, measure the E+ of the sensor to S+, S- (or E-to S+, S-) or not, generally the error is 0.5 For Ω or more, compensation is required. If the error is too large (more than 2 Ω), it is recommended to replace L/C. b. Dynamic quantity method: connect the sensor wiring correctly to the motherboard, and use the digital meter (more than four and a half better) DCV file to measure whether the voltage of S+ to ground and S-ground is equal (preferably 0 error), if not equal, sensor compensation is required. 9. Electronic balance angle coupling adjustment (single sensor) a. Perform weight correction first. b. Measure the displayed value at the four corners of the weighing pan with the full load of 1/3 weight. c. Use the boring tool to grind the 1st to the 4th angle and press the zero. (When grinding the scale for the first time, please test its force with a small force test to avoid damage to the sensor) d. Repeat 2~3 movements until the center of the weighing pan is within ±1 hop with the center as the reference error, and then make the weight correction. e. If the error of the four corners of the weighing pan is too large and it is too large after grinding the scale, it means that the sensor is faulty or the grinding scale method is wrong. f. Pay attention to the sensor specifications when grinding the scale. The lighter the full load, the lighter the grinding force. 10. Electronic scale sensor compensation a. If the sensor output signal is too high, please add a resistor (50K~2.2MΩ depending on the situation). The signal between the sensor's "E+S-" will make the value to the normal range (the lower the resistance value = the lower the sensor output signal) . b. The sensor output signal is too low or -ERR please add a resistor (50k~2.2MΩ depending on the situation) to make the signal value to the normal range between the sensor's "E+~S+" (the lower the resistance value = the more the sensor output signal high). Appendix: Method for detecting A/D circuit amplification code The electronic scale is debugged to the internal setting state (to display the current internal code state), and the full weighing weight is applied to record the amplified code value, and their relationship: bottom code value + full scale amplification code + safe area code electronic . 11. Electronic scale display backlight is invalid a. insufficient battery power b. The current weighing is less than the minimum weighing 12. Electronic scales start to tweet a. Sensor connection is damaged b. Set the checkweighing 13. The electronic scale starts “HHHHH†and has a fixed weight value. a. Sensor overload b. The electronic scale weighing pan is not placed well c. Weight calibration is required d. Need to replace the sensor 14. When the electronic scale is weighed, the result is unstable. a. The sensor or instrument is faulty b. The environment in which the balance is placed is too bad c. The parameter settings in the electronic scale menu are not good. d. The temperature of the object being weighed is not equal to the temperature of the electronic scale e. Samples have water absorption or water release / static / magnetic characteristics 15. Electronic barcode scale cannot print a. The printer type is wrong b. The printer connection is not plugged in, please count the number, the stability mark is not bright. c. Is the printer connected, and the printer power is plugged in?
b. Not within the standard, please refer to the tenth item for compensation.
d. Please follow the instructions to do weight correction.