A timing signal diagnostic system includes a chassis housing an input system that receives a timing signal, a timing system that receives the timing signal from the input system, an analog-to-digital converter system that receives the timing signal from the input system, and a processing system that is coupled to the timing system and the analog-to-digital converter system. The processing system uses the timing system to output reference time signals to the analog-to-digital converter system that are based on the timing signal, and uses the analog-to-digital converter system to sample the timing signal based on the reference time signals over a plurality of different timing signal cycles. Based on the sampling of the timing signal, the processing system generates a waveform for the timing signal, and provides a timing signal diagnostic result based on the waveform for the timing signal.