Fix a position according to measuring curve:
Basis: exceeding disturbance frequency range, exceeding disturbance frequency domain distribution, narrow-band harassment or broadband harassment, etc
Fix a position according to the measured equipment work mode and internal structure.
Have the half-wave rectifier which is not advised to use by standard and symmetric / asymmetric power adjustment circuit been used?
Is the internal layout of the circuit board reasonable？
Is the internal running cable reasonable？
Is the installation of the internal filter (filter circuit) reasonable?
Are the grounding of internal circuit and lapping method reasonable?
Does the chassis shield meet the demand of the corresponding products?
Fix a position according to the measured equipment composition and function:
Are there secondary power system and operation mode in the device?
Whether there is a drive motor, motor type in the device?
If there is variable-frequency control of motor speed circuit in the device.
Is there digital control or intelligent control circuit in the device? Whether to use crystal oscillator?
Whether there is programmed relay or switch circuit in the device.
Whether the electromagnetic wave or microwave is used when the equipment is working normally.
Is there wireless transceiver circuit of working in the device?
Fix the fault position according to the working condition of function module:
If each module of the equipment can stop working and restart to work, the harassment can be found by stopping these modules from working one by one.
If the module can’t stop working and restart to work independently, we can make it work together with other function module, stop and restart to work, and then the harassment probable source can be found.
For the modules which suspect the harassment exceeding standards, we can take the substitution measures to judge the harassment.