Electronic scale does not return to zero

A. Check whether the sensor output signal value is within the standard. (A/D's total magnification code/internal code range/base code range) B. If it is not in the standard, please refer to item 10 for compensation. C. If it cannot be compensated, please check whether the sensor is defective. (please follow item 8 for testing) D. Please do m school 1 according to the instruction manual.