Sweep Frequency Response Analysis (SFRA) testing has become a valuable tool for verifying the geometric integrity of electrical apparatus, specially transformers. The SFRA technique provides internal diagnostic information using non-intrusive procedure. Power Transformers are specified to withstand the mechanical forces arising from both shipping and subsequent inservice events, such as faults and lightning. Transportation damage may lead to core and winding movement. This research is undertaken to study and diagnosis the failure of power transformer by investigation of transformer mechanical integrity using the Doble's M5200. This paper presents case studies related to the SFRA testing, & their result interpretation through the statistical indicator and the standard interpretations available.