Hi Sen,
When loading the rasters into a mosaic dataset, make sure you are using a UNC path (i.e. \\server\data\rasters\TIFFs). If you use the absolute path (C:\data\rasters\TIFFs), the client machine will look locally for the raw imagery when zooming into a large scale producing the checkerboard pattern you're experiencing. The UNC path will ensure the client is pulling the imagery from the correct server.
