Sure, that is very true during development or debugging a complex production issue as you mentioned. I meant troubleshooting and reworking along the lines of "t

Sure, that is very true during development or debugging a complex production issue as you mentioned. I meant troubleshooting and reworking along the lines of "this board used to work, now it doesn't". Most reworks I see of boards involve replacing parts, which in a modern Ethernet design would consist of the jack, some magnetics, PHY, and SoC.