Personally I'm just a hobbyist, and enjoy the success I'm getting with practical circuits, that I can use with my amateur radio station, yes I have failures, also I'm doing the theory, in bite size pieces, and learning pic programing as well, my present endeavour is a pic based frequency counter, and I'm learning so much from it, I have a couple of old radio's I have here and at some stage fault find. the 4 engineers, don't do digital stuff , there field seems to be tube amps, old TV's pre surface mount, and a awful lot of restoration work, so it's not the high tech, one of them as I recall does do video recorders and camcorders, none of it is digital though, if it is it's the early stuff.