Manually test computer Ethernet port with a multimeter
You can do some tests with a multimeter but you can't fully test functionality.







simulate this circuit &ndash; Schematic created using CircuitLab

A correctly working gigabit ethernet socket will show continuity (low resistance) betweens pins 1 and 2, between pins 3 and 6 , between pins 4 and 5 and between pins 7 and 8, it will show no other connections, including from pins to ground.

The easiest way to test an ehternet socket is to connect it to another known good ethernet socket using a known good cable, and then check the link lights at both ends.