For research use only. Not for use in diagnostic procedures.
Some common signs of a bad ethernet cards include:
1) The card disappears from the computer configuration.
2) The card becomes corrupt after a Windows OS update.
3) A small light on the card showing 100xit will be lit when the cable is plugged in.
Ethernet card performance can be affected by dust inside the PC or on the cooling fan, so regular internal computer maintenance is required to remove the dust that builds up on the microprocessor. Dust buildup can also cause components to become overheated, and this would damage the ethernet card as well.
A good ethernet card connection can be "pinged" when testing the physical connection of the card to the instrument.