A comprehensive malfunction in the CINRAD/SA weather radar servo system at Jinan occurred from 21:00 28 May to 13:00 31 May 2008, involved the digital control unit (DCU), fiber communication link and data attainment unit (DAU) of the antenna servo system. By means of the conventional approaches, the malfunction can not be removed. Through taking the digital control unit state display and corner brace display as key points, the causes of the malfunction were reexamined one by one, so to make the radar return to normal. The causes and inspection and repair ideas of the malfunction are discussed, and the results can be used as references in improving the capability of the radar maintenance staff.