After months of developing your latest design using the best tools at your disposal, it’s reality time. The prototype has arrived and is ready for testing. All your careful development work, rigid design rules, signal integrity analysis and presimulation passes will ensure the prototype will work to specification with little chance of needing design revisions – what’s more, it even looks great!
But when you power it up, a major section doesn’t work as expected. The next step is probably cursing, followed by a process of diagnosing and correcting the problem. That will generally involve a gaggle of test instruments linked to flying probes. This, coupled with the design documentation and your troubleshooting skills, allows you to trace signals around the populated board to deduce the culprit.
