在HP笔记本电脑上的Ubuntu 14.04上未检测到WiFi

我遇到了WiFi问题。我无法连接到任何WiFi网络，也没有列出我的Wifi适配器。

请不要将此问题标记为重复。我访问了论坛上的所有答案，但问题仍未解决。因此，我提出了这个查询。

首先，我在这里访问并实现了最佳答案，但仍然对我没有任何帮助。

几个基本命令的输出：

    saloni@saloni-HP-Pavilion-15-Notebook-PC:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 6c:c2:17:7a:53:e6  
          inet addr:192.168.55.26  Bcast:192.168.55.255  Mask:255.255.255.0
          inet6 addr: fe80::6ec2:17ff:fe7a:53e6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:34311 errors:0 dropped:298 overruns:0 frame:0
          TX packets:21509 errors:0 dropped:47 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:9422260 (9.4 MB)  TX bytes:3237112 (3.2 MB)

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:3543 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3543 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:521328 (521.3 KB)  TX bytes:521328 (521.3 KB)

saloni@saloni-HP-Pavilion-15-Notebook-PC:~$ lspci -nn | grep Network
08:00.0 Network controller [0280]: Broadcom Limited BCM43142 802.11b/g/n [14e4:4365] (rev 01)

对于BCM43142，我安装了bcmwl-kernel-source软件包。

 saloni@saloni-HP-Pavilion-15-Notebook-PC:~$ sudo apt-get upgrade bcmwl-kernel-source
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
bcmwl-kernel-source is already the newest version.
The following packages were automatically installed and are no longer required:
  linux-headers-4.4.0-31 linux-headers-4.4.0-31-generic linux-headers-4.4.0-62
  linux-headers-4.4.0-62-generic linux-image-4.4.0-31-generic
  linux-image-4.4.0-62-generic linux-image-extra-4.4.0-31-generic
  linux-image-extra-4.4.0-62-generic linux-signed-image-4.4.0-62-generic
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

最新版本已经安装。我仍然看不到中列出的任何Wifi卡ifconfig。

rfkill无线卡也没有开关。

    saloni@saloni-HP-Pavilion-15-Notebook-PC:~$ rfkill list all
0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no

还，

saloni@saloni-HP-Pavilion-15-Notebook-PC:~$ sudo ifup wlan0
Ignoring unknown interface wlan0=wlan0.

我的笔记本电脑上没有硬件WiFi启用/禁用开关。而且WiFi在Windows 8.1上也能正常工作（我是双启动）。

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@ Pilot6要求您执行此操作：

saloni@saloni-HP-Pavilion-15-Notebook-PC:~$ lspci -knn | grep Net -A3
08:00.0 Network controller [0280]: Broadcom Limited BCM43142 802.11b/g/n [14e4:4365] (rev 01) 
Subsystem: Hewlett-Packard Company Device [103c:2230] 
09:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [10ec:8136] (rev 08)
Subsystem: Hewlett-Packard Company Device [103c:2281]