The digital microfluidics technology has shown a great progress in the recent years. The testing of these types of biochips is crucial when used in widespread applications like clinical diagnostics, DNA sequencing, toxicity analysis etc. Thus these biochips must be tested adequately both offline after manufacturing and online during the biomedical assay. The MEDA based digital microfluidics offers a promising potential in future due the advanced fluidics operations associated with it. Conventional testing of digital microfluidics encounters some of the defects which require diagonal movement of test droplet to detect them. This paper describes the advanced fluidics operations of MEDA based biochips followed by a defect diagnosis methodology for conventional digital microfluidics based on the diagonal movement of MEDA based biochips. Analysis of the approach is done with the well-known parallel scan like testing method.