Troubleshooting hints when the ethernet cable is not detected.
Irrespective of which of the 2x onboard Network Interface Card (NIC) ports one connects the cable to, the Light-emitting diodes (LEDs) on them do not turn on at all, as though they would not detect the presence of the cable.
If a cable is connected to any of the onboard NIC ports, the Link/Activity LED should not stay off. This should either be On indicating network connection or, when blinking, means it is in transmit/receive activity. This is indicated on the Technical Product Specification for the board.
In light of the above fact, the following analysis should help diagnose the reason why the LED is off:
- Ensure the Basic Input/Output System (BIOS) NIC Controller option is set to Enabled. This is found under the Advanced/PCI Configuration/NIC Configuration menu.
- Load up the BIOS default settings.
- Ensure the BIOS/firmware is the latest.
If these above steps do not resolve the situation, please, contact Intel Customer Support with the system event logs.
Related Topic of Interest: See also LAN Leash has been lost security sensor event in the System Event Log Troubleshooting Guide.