What's Old Is Still New

Back in the day when I was one of those tech's whose job involved the "joy" of reworking defective boards, I longed for self test capabilities. Ultimately some clever software engineers designed self test routines which not only reduced my diagnostic headaches to a minimum but provided valuable information for design improvements.

I'm out on a limb here but it seems to me with the abundance of cheap CPU's or other logic capapable devices, board testing could be entirely automatic. The concept of highjacking the on board logic device (CPU or whatever) for self test diagnostics is well developed in the cardiac assist device (pacemakers and implantable defibrillators) industry.

Complex testing devices are still used for wafer levels diagnostics but most assemblies are now tested by on board diagnostic routines. With the shrinkage of component sizes, manual repair has become the provence of stereomicroscopes and delicate surgical techniques.

Back in the 90's programmers developed "self repair" sub routines which used excess capabilities to work around problematic areas. Now that philosophy has been expanded to allow these devices to continue functioning in limited life saving modes even after significant "battle damage".