Eu tenho um problema semelhante com a minha Lenovo, tanto na conexão wifi quanto na ethernet, aqui está o resultado do comentário que você fez:
*-network
description: Ethernet interface
product: Ethernet Connection I217-LM
vendor: Intel Corporation
physical id: 19
bus info: pci@0000:00:19.0
logical name: eth0
version: 04
serial: 04:da:d2:bf:2c:ac
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=2.3.2-k firmware=0.13-3 latency=0 link=no multicast=yes port=twisted pair
resources: irq:45 memory:b2a00000-b2a1ffff memory:b2a3f000-b2a3ffff ioport:5080(size=32)
*-network
description: Wireless interface
product: Wireless 7260
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlan0
version: 83
serial: 5c:51:4f:9e:a1:c9
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=3.13.0-74-generic firmware=22.24.8.0 ip=192.168.1.12 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
resources: irq:47 memory:b2800000-b2801fff
Eu tentei reiniciar o computador, parando-o, removendo a bateria e reiniciando-a. Tentei reiniciar a caixa também.