The failure in a transmitter of the new generation weather radar CINRAD/CD modulation system can affect the radar signals and even result in complete breakdown of the radar system. Two typical faults in the transmitter of the new generation weather radar CINRAD/CD modulation system are described, and the symptoms are analyzed in combination with the practical experiences, through step by step judging, checking, and testing the key circuit signals according to the composition and working principles of the modulation system, to identify the basic causes of failure and locate quickly the failure and then take the corresponding countermeasures.