Abstract: A system and method is disclosed for communications connectivity failure diagnosis that includes receiving a connectivity failure notice at an on-line center indicative of a communications failure between the on-line center and an in-field product, such as a medical diagnostic device. A software-based non-connect test is manually initiated to confirm a communications failure between the on-line center and the in-field product. Once the communications failure is confirmed, the communications failure is diagnosed by isolating the communications failure through use of the non-connect test and identifying a failure type which indicates what portion of the system failed. The method includes reporting the communications failure for repair, and once repaired, the system conducts a series of tests to confirm proper connectivity and logs the results therefrom.