WAN ports on a router connect to external networks.
WAN ports on a router connect to external networks.
It could be anything along the wires, from accidental damage to ground cuts or loose connections causing sparks. The ISP's equipment is robust and includes surge protection for Ethernet lines, but other devices connected to those lines might still be affected.
The incoming signal from the ISP varies compared to what reaches the router. Based on the configuration, the modem gathers data from different sources like twisted pair, coaxial cable, or fiber and converts it into a standard Ethernet format. If significant voltage fluctuations appear over the WAN port, it indicates a faulty modem. This usually happens with regular ISP modems unless you have a combined modem/router setup or a specialized system such as FTTH, where the entire copper network stays inside the premises. EDIT: Excessive power from the pole or improper wiring returning to the ISP can damage the modem, not the router.
It didn’t burn completely and turned a solid black color as expected from heat and pressure, but it’s no longer functioning properly. Just the Lan ports are still operational.