There is a device called the "Leak Seeker". It is normally used to=20 find shorts on PCBs but could also be used to find where a trace=20 suddenly goes open. This assumes, of course, that you do have access=20 to all of the points on a trace where you want to check. For traces on inner layers, about all you can check with this device=20 is component nodes and vias. It won't find the exact location of a=20 break on a trace in an inner layer - all you can do is find that the=20 trace is open between two accessible points on the trace. The reason that I mention this device is that user feedback is an=20 audible tone that changes pitch as you move the probe tips closer or=20 further away from each other. It is sensitive to milli-Ohm changes. dwayne At 07:23 PM 11/20/2016, Harold Hallikainen wrote: >We occasionally find an open PCB trace (or perhaps via). Of course, the >problem is on an inner layer. We can tell from continuity measurements >that we have a problem between one via and the next. But where is the >break? At one of the vias, on the trace? Is there a tracing device where >we can inject a signal at a via and then follow it down the trace? I've >seem something like this for tracing cable pairs in telephone cables. Is >there something like this to find a problem in a PCB? > >Thanks! > >Harold --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA 780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .