I believe it is a Realtek LAN adapter on these.. I would update the BIOS, and install the latest "Networking/LAN" driver for your machine from Lenovo:
There should be no need for "cable" when installing the driver?
The adapter should be visible in Device Manager, and the icon in the system tray. If it is not recognized, it either has the wrong driver installed for it, or it may be faulty hardware. If it is faulty, opening up the laptop may be required.