Based on the facts that there are no echo signals in CINRAD/CC Radar in the past few years, the faults in the antenna subsystem, launch subsystem, receiving subsystem, and signal processing subsystem are sorted and analyzed. It is found that the faults have different properties. According to the receiving flow of radar echo signals and the working principles of each subsystem, by using classification and gradual diagnostic methods, the maintenance methods for faults without echo signals for each subsystem are described through analyzing radar status parameters. Some test data and waveforms of key points are also provided as references for maintenance. Technicians can eliminate faults and maintain equipment based on these indexes in practical work. Taking Puer Station as an example, the procedures to eliminate faults are described according to the terminal parameters and the variation of parameters at monitoring points. Based on the signal flow, the fault was eliminated through the segmental measurement and analysis of key points. The process of the fault elimination is summarized, which is of reference value for the related professionals.