Gfilui

My dual boot Lenovo Yoga Thinkpad has a Broadcom 43142 wireless card and got poor reception compared to other computers. So I tried a USB antenna by turning off the Broadcom card in the Additional Drivers application with do not use this device. Then when I tried to turn it back on, it did not turn on. Since then I have not been able to see any wifi networks in Ubuntu.

The Windows partition wifi is still OK and so I know the wifi card works.

After trying several suggestions in Ubuntu help threads, I gave up. At this point, I had the 15.10 version and because I had been planning to upgrade to 16.04 anyway, I made a bootable disk with the iso file in Ubuntu downloads (amd64) and installed it deleting the 15.10 version.

Even in the new OS, the network is off with no wifi networks showing. The no networks available is not bright, enable networking is on. The Additional Drivers window has the Broadcom driver highlighted and shows device is in use.

I dont understand what they really mean, but I have tried all the tricks that are given in the Ubuntu threads which have "no network ", "no network devices", "no internet", "Broadcom 43142", "wifi not available" etc.

Examples I tried are :

• Toggled different combinations of the logic statements in NetworkManager.conf and NetworkManager.state, restarting every time.




• sudo systemctl restart network-manager



• 
  

  sudo service network-manager restart

  
  
  

  (These turn off even the highlights of Enable Networking and Edit connections. Rebooting restores these).

  
  



• sudo rm /var/lib/apt/lists/lock and 2 other locks




• I installed a different Linux kernel (got the file name from one of these pages) and tried again.



• 
  

  Then I gave up on these and decided to delete the current driver and install the driver bcmwl-kernel-source_6.30.223.248+bdcom-0ubuntu8_amd64.deb (which is shown to be for the 16.04 LTS):

  
  
  

  sudo apt-get purge bcmwl-kernel-source
  sudo dpkg -i bcmwl-kernel-source_6.30.223.248+bdcom-0ubuntu8_amd64.deb
  

  
  
  

  Nothing changed.

  
  

Finally I checked the ribbon connection to the wireless card. It was fine.

The laptop does not have an Ethernet port, so cannot try any "apt-get" options.

Please note that in the network description, the wireless card has no name and shows latency=0.

Diagnostics results (Sorry for the length - no way to attach a file here, I think.)

$ lshw -C network 

*-network UNCLAIMED
 description: Network controller
 product: BCM43142 802.11b/g/n
 vendor: Broadcom Corporation
 physical id: 0
 bus info: pci@0000:01:00.0
 version: 01
 width: 64 bits
 clock: 33MHz
 capabilities: pm msi pciexpress cap_list
 configuration: latency=0
 resources: memory:d0400000-d0407fff

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$more /etc/NetworkManager/NetworkManager.conf

[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq

[ifupdown]
managed=true

----
$more /var/lib/NetworkManager/NetworkManager.state

[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
-----
$lspci

00:00.0 Host bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series SoC Transaction Register (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display (rev 0c)
00:13.0 SATA controller: Intel Corporation Atom Processor E3800 Series SATA AHCI Controller (rev 0c)
00:14.0 USB controller: Intel Corporation Atom Processor Z36xxx/Z37xxx, Celeron N2000 Series USB xHCI (rev 0c)
00:1a.0 Encryption controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Trusted Execution Engine (rev 0c)
00:1b.0 Audio device: Intel Corporation Atom Processor Z36xxx/Z37xxx Series High Definition Audio Controller (rev 0c)
00:1c.0 PCI bridge: Intel Corporation Atom Processor E3800 Series PCI Express Root Port 1 (rev 0c)
00:1f.0 ISA bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Power Control Unit (rev 0c)
00:1f.3 SMBus: Intel Corporation Atom Processor E3800 Series SMBus Controller (rev 0c)
01:00.0 Network controller: Broadcom Corporation BCM43142 802.11b/g/n (rev 01)

$ rfkill list
0: ideapad_wlan: Wireless LAN
 Soft blocked: no
 Hard blocked: no
1: ideapad_bluetooth: Bluetooth
 Soft blocked: no
 Hard blocked: no
3: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no
------
$lsmod | grep ideapad
ideapad_laptop 32768 0
sparse_keymap 16384 1 ideapad_laptop
wmi 24576 1 ideapad_laptop
video 40960 3 int3406_thermal,i915,ideapad_laptop
-------
$ifconfig
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:10116 errors:0 dropped:0 overruns:0 frame:0
 TX packets:10116 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000 
 RX bytes:748720 (748.7 KB) TX bytes:748720 (748.7 KB)
------

$iwconfig

lo no wireless extensions.

No blacklisting of bcmwl ..is seen any blacklists in /etc/modprobe.d
$more blacklist-bcm43.conf
# Warning: This file is autogenerated by bcmwl. All changes to this file will be
 lost.
blacklist b43
blacklist b43legacy
blacklist ssb
blacklist bcm43xx
blacklist brcm80211
blacklist brcmfmac
blacklist brcmsmac
blacklist bcma
----

$ dmesg | grep -i firmware
[ 0.000000] [Firmware Bug]: TSC ADJUST: CPU0: -78526968 force to 0
[ 0.004000] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -78526968 CPU1: 0
[ 0.004000] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -78526968 CPU2: 0
[ 0.004000] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -78526968 CPU3: 0
[ 0.118743] acpi PNP0A08:00: [Firmware Info]: MMCONFIG for domain 0000 [bus 00-3f] only partially covers this bridge
[ 2.338406] psmouse serio1: elantech: assuming hardware version 4 (with firmware version 0x695f02)
[ 14.780659] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2
[1266874877.614749] [Firmware Bug]: TSC ADJUST differs: CPU0 0 --> -83133778. Restoring
[ 1040.841006] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -78526968 CPU1: 0
[ 1040.841742] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -78526968 CPU2: 0
[ 1040.842525] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -78526968 CPU3: 0
[ 1042.741187] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2

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