Abstract: In a specific embodiment of the present invention, a graphics device generates digital output data in response to a known input data. The resulting digital output data has an expected circular redundancy check (CRC) value. The generated digital output data is provided to a digital graphics output port associated with the graphics controller, which is thereby transmitted to a test apparatus over a digital graphics cable. The test apparatus performs an analysis on the received digital graphics data. The analysis results are transmitted back to the graphics device over a serial link of the digital display cable. The graphics device receives the transmitted analysis data, which is subsequently used to determine if the graphics device is operating properly. This determination may be made the graphics device, or by a host system for further analysis.