Since the CINRAD/SA weather radars run operationally, many special malfu nctions have appeared in the antenna and servo systems. Some special malfunctions of ant enna and servo system are selected from some CINRAD/SA weather radars including Lianyungang weather radar, which result in PUP picture abnormity. The causation is detected, by using the RDASOT test program, measuring the feedback voltage of the electromotor which is for measuring the rate, and analyzing the base data o f the radar.