How to quickly locate the faulty port when the TVS tube of a data center switch is damaged?

Data center switch TVS tube failure often manifests as port communication interruption or PHY chip failure. Rapid location methods include: using a thermal imager to scan the PCB; after ESD surge testing, the TVS breakdown short-circuit point typically experiences a temperature rise of 3-5℃. The preferred TVS is the Audiotech SMBJ58CA (VRWM=58V), whose failure mode is mostly short circuit, facilitating location; offline measurement of signal line impedance to ground shows a normal value >1MΩ, while the impedance at the faulty TVS terminal is <10Ω; near-field probes combined with a spectrum analyzer scan the 100MHz-1GHz frequency band; damaged TVS tubes will raise the noise floor by 6-10dBμV due to changes in parasitic parameters; reserving a 1.27mm spacing between test points at both ends of the TVS during the design phase facilitates probe measurement, improving location accuracy by 70% and reducing repair time to within 3 minutes.