我买了一台戴尔 Latitude E7470，它默认预装了 Ubuntu 1404。第一天，Wi-Fi 工作正常，但第二天在接受了推荐的软件更新之一后，它完全停止工作了。笔记本电脑无法识别和显示任何可用网络。此外，以太网也无法工作，这本身也是一个问题，而且由于我根本没有连接，安装任何缺失的驱动程序变得更加困难。
在网上搜索时，我发现了这个离线安装驱动程序的方案。我没有安装盘，所以我使用了那里的链接。但它不起作用（重启后）。 如何离线安装 Broadcom 无线驱动程序？
我认为从现在起我真的需要一些具体的帮助。目前，我正在来回移动故障机器和我有连接的另一台机器的命令行输出。以下是在其他类似的 Ubuntu/互联网问题中被证明有用的一些信息：
lspci 的输出
00:00.0 Host bridge: Intel Corporation Sky Lake Host Bridge/DRAM Registers (rev 08)
00:02.0 VGA compatible controller: Intel Corporation Sky Lake Integrated Graphics (rev 07)
00:04.0 Signal processing controller: Intel Corporation Device 1903 (rev 08)
00:14.0 USB controller: Intel Corporation Device 9d2f (rev 21)
00:14.2 Signal processing controller: Intel Corporation Device 9d31 (rev 21)
00:16.0 Communication controller: Intel Corporation Device 9d3a (rev 21)
00:17.0 SATA controller: Intel Corporation Device 9d03 (rev 21)
00:1c.0 PCI bridge: Intel Corporation Device 9d14 (rev f1)
00:1d.0 PCI bridge: Intel Corporation Device 9d1a (rev f1)
00:1f.0 ISA bridge: Intel Corporation Device 9d48 (rev 21)
00:1f.2 Memory controller: Intel Corporation Device 9d21 (rev 21)
00:1f.3 Audio device: Intel Corporation Device 9d70 (rev 21)
00:1f.4 SMBus: Intel Corporation Device 9d23 (rev 21)
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection I219-LM (rev 21)
01:00.0 Network controller: Intel Corporation Wireless 8260 (rev 3a)
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 525a (rev 01)
输出lshw -C network：
*-network UNCLAIMED
description: Network controller
product: Wireless 8260
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:01:00.0
version: 3a
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress cap_list
configuration: latency=0
resources: memory:e1100000-e1101fff
*-network UNCLAIMED
description: Ethernet controller
product: Ethernet Connection I219-LM
vendor: Intel Corporation
physical id: 1f.6
bus info: pci@0000:00:1f.6
version: 21
width: 32 bits
clock: 33MHz
capabilities: pm msi cap_list
configuration: latency=0
resources: memory:e1200000-e121ffff
输出nm-tool：
NetworkManager Tool
State: disconnected
输出ifconfig -a：
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1184 (1.1 KB) TX bytes:1184 (1.1 KB)
/var/lib/NetworkManager/NetworkManager.state**：
[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
WimaxEnabled=true
/etc/NetworkManager/NetworkManager.conf**：
[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq
[ifupdown]
managed=false
/etc/udev/rules.d/70-persistent-net.rules**：
# This file was automatically generated by the /lib/udev/write_net_rules
# program, run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single
# line, and change only the value of the NAME= key.
# PCI device 0x8086:0x156f (e1000e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="18:db:f2:18:38:56", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
# PCI device 0x8086:0x24f3 (iwlwifi)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="e4:a7:a0:d8:69:4f", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="wlan*", NAME="wlan0"