No wi-fi adapter found - Ubuntu 18.04.2 LTS

wireless

10,623

Solution 1

Solved - point release (18.04.3 LTS) of OS fixed issue.

Solution 2

In terminal...

sudo pico /etc/netplan/config.yaml # create/edit the file

Enter the following text using copy/paste...

network:
  version: 2
  renderer: NetworkManager

Save the file. Exit the editor.

sudo netplan --debug generate # generate config files

sudo netplan apply # apply configuration

sudo lshw -C network # check to see if wlan0 is NOT DISABLED

Copy/paste the output of the above three commands into your question so I can take a look.

reboot # reboot the computer

Check wireless operation using the standard NetworkManager GUI menu.

Update #1:

Re-seat the PCI wifi card.

Check to see if you have a function key to enable/disable wireless.

Check to make sure the airplane mode is off...

Solution 3

If Wi-Fi mysteriously disappeared without trace after your laptop was been left for a little time while not charging, and shows the symptoms described in this question despite having correct, up-to-date drivers etc: check that Ubuntu hasn't just slyly disconnected the Wi-Fi adapter to save power.

Go to the "Power" section of settings and check the switch labelled "Wi-Fi Turn off Wi-Fi to save power" is turned on.

The labelling here is potentially confusing. This is a toggle for Wi-Fi itself, and it might be automatically flipped off by the OS to save power. It does not control that "Turn off Wi-Fi to save power" feature.

If this switch is on, Wi-Fi is on as normal
If this switch is off, Wi-Fi is disabled completely and disappears from the places you might normally look to manage the Wi-Fi.
- Wi-Fi settings displays nothing but "No wi-fi adapter found"
- The top right system tray alternates between an "airplane mode" icon that does not restore wifi on disabling airplane mode, and simply not mentioning wifi as if this is a laptop with no wifi adapter,
- nmcli device status lists no "wi-fi" device at all
It appears that there is no simple control to disable the feature of disabling Wi-Fi to save power (if I find one I'll edit it in)

Update: this worked for me a couple of times, but just now I had the same problem of WiFi disappearing after suspend, but this time the WiFi option was even missing from the "Power" settings screen. Nothing in ifconfig -a (missing wlo1 entry), or rfkill list (showed bluetooth only, missing Wireless LAN entry), or sudo lshw -C network (listed only Ethernet, missing Wireless interface entry).

The only thing that worked for me this latest time was restarting the laptop.

10,623

Author by

deltapie

Updated on September 18, 2022

Comments

deltapie over 1 year

Not sure what happened, but i'm no longer able to utilize my PCI wifi adapter. Thoughts? Thank you so much for any help or direction you can provide.

Ubuntu 18.04.2 LTS

lshw -C network results:

*-network DISABLED        
       description: Wireless interface
       product: AR93xx Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 01
       serial: 68:1c:a2:06:2d:99
       width: 64 bits
       clock: 33MHz
       capabilities: bus_master cap_list rom ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=4.15.0-48-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:17 memory:fdec0000-fdedffff memory:fde00000-fde0ffff

rfkill list results:

0: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no

**Within settings**:

No wi-fi adapter found

sudo lshw -C network

  *-network DISABLED        
       description: Wireless interface
       product: AR93xx Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 01
       serial: 68:1c:a2:06:2d:99
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=4.15.0-48-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:17 memory:fdec0000-fdedffff memory:fde00000-fde0ffff
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: eth0
       version: 0c
       serial: 40:8d:5c:74:2d:91
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168g-2_0.0.1 02/06/13 ip=192.168.86.71 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s
       resources: irq:18 ioport:de00(size=256) memory:fdcff000-fdcfffff memory:fdbfc000-fdbfffff

cat /etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

cat /etc/netplan/*.yaml

cat: '/etc/netplan/*.yaml': No such file or directory

nmcli device show wlan0

Note: I tried nmcli device show wlan0 | grep IP4.DNS and nothing displayed

GENERAL.DEVICE:                         wlan0
GENERAL.TYPE:                           wifi
GENERAL.HWADDR:                         68:1C:A2:06:2D:99
GENERAL.MTU:                            1500
GENERAL.STATE:                          10 (unmanaged)
GENERAL.CONNECTION:                     --
GENERAL.CON-PATH:                       --
IP4.GATEWAY:                            --
IP6.GATEWAY:                            --

sudo lshw -short -class network

H/W path            Device      Class       Description
=======================================================
/0/100/5/0          wlan0       network     AR93xx Wireless Network Adapter
/0/100/6/0          eth0        network     RTL8111/8168/8411 PCI Express Gigabi

lspci -k | grep -A

grep: option requires an argument -- 'A'
Usage: grep [OPTION]... PATTERN [FILE]...

-i "Network controller"

-i: command not found

ls -l /etc/resolv.conf

lrwxrwxrwx 1 root root 29 Jan 31  2016 /etc/resolv.conf -> ../run/resolvconf/resolv.conf

ls -al /etc/netplan

total 16
drwxr-xr-x   2 root root  4096 Nov 21 13:42 .
drwxr-xr-x 158 root root 12288 Apr  4 22:42 ..

sudo ifconfig wlan0 up

Nothing display

Started to have this impact after an upgrade (I assume - didn't notice it right away, but did an upgrade not that long ago).

ubuntu@ubuntu:~$ sudo pico /etc/netplan/config.yaml [sudo] password for ubuntu: ubuntu@ubuntu:~$ sudo netplan --debug generate

DEBUG:command generate: running ['/lib/netplan/generate']
** (generate:19312): DEBUG: 21:03:25.159: Processing input file /etc/netplan/config.yaml..
** (generate:19312): DEBUG: 21:03:25.159: starting new processing pass
** (generate:19312): DEBUG: 21:03:25.159: Generating output files..

ubuntu@ubuntu:~$ sudo netplan apply ubuntu@ubuntu:~$ sudo lshw -C network

*-network                 
       description: Wireless interface
       product: AR93xx Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 01
       serial: 68:1c:a2:06:2d:99
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=4.15.0-48-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:17 memory:fdec0000-fdedffff memory:fde00000-fde0ffff
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: eth0
       version: 0c
       serial: 40:8d:5c:74:2d:91
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168g-2_0.0.1 02/06/13 ip=192.168.86.71 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s
       resources: irq:18 ioport:de00(size=256) memory:fdcff000-fdcfffff memory:fdbfc000-fdbfffff

April 9th 9:13CT

lspci -k | grep -A 4 -i "Network controller"

03:00.0 Network controller: Qualcomm Atheros AR93xx Wireless Network Adapter (rev 01)
    Subsystem: Qualcomm Atheros AR93xx Wireless Network Adapter
    Kernel driver in use: ath9k
    Kernel modules: ath9k, wl
04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)

rfkill unblock all

sudo lshw -C network

  *-network DISABLED        
       description: Wireless interface
       product: AR93xx Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 01
       serial: 68:1c:a2:06:2d:99
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=4.15.0-48-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:17 memory:fdec0000-fdedffff memory:fde00000-fde0ffff
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: eth0
       version: 0c
       serial: 40:8d:5c:74:2d:91
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168g-2_0.0.1 02/06/13 ip=192.168.86.71 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s
       resources: irq:18 ioport:de00(size=256) memory:fdcff000-fdcfffff memory:fdbfc000-fdbfffff

April 11th 10:21 pm CT

Re-seated wifi card and took the following screen shot: no wifi

Boris Hamanov about 5 years

Edit your question and show me sudo lshw -C network and cat /etc/network/interfaces and cat /etc/netplan/*.yaml. Report back to @heynnema
deltapie about 5 years

@heynnema updated my post. Thanks so much for looking at it.
Marmayogi about 5 years

Please edit your question and post the output of the following commands: 1. nmcli device show wlan0 | grep IP4.DNS 2. sudo lshw -short -class network and 3 lspci -k | grep -A 4 -i "Network controller" and 5. ls -l /etc/resolv.conf
Boris Hamanov about 5 years

Curious that /etc/netplan didn't have any .yaml files. Try ls -al /etc/netplan. Was this an upgrade, or fresh install? Is airport mode enabled? Try sudo ifconfig wlan0 up.
deltapie about 5 years

Updated original post with all requested commands. Noticed this shortly after an upgrade (but admit I didn't notice right away). I do not see an option for airport mode (desktop computer). @heynnema
deltapie about 5 years

@Marmayogi I edited the orginal post with the requested commands. thanks for the help!
Boris Hamanov about 5 years

@deltapie give me a couple of minutes to put together an answer for you...
Boris Hamanov about 5 years

@deltapie Done. Do my answer. Report back.
Marmayogi about 5 years

@deltapie, please re-issue this command: lspci -k | grep -A 4 -i "Network controller" and post output.
Marmayogi about 5 years

@deltapie, please issue this command rfkill unblock all and reboot. Now check whether Wi-Fi enabled or not by trying to connect to internet.
deltapie about 5 years

Sorry it took me so long to reply. New to the forum and didn't notice the reply (so very sorry). Did the above commands, rebooted, still no wireless card shown in UI settings menu.
Boris Hamanov almost 4 years

@deltapie Did you ever get this problem resolved?

deltapie about 5 years

Posted the results in the original post. After reboot "no wi-fi adapter found. Make sure you have a wi-fi adapter plugged and turned on"
deltapie about 5 years

After reboot: sudo lshw -C network *-network DISABLED description: Wireless interface
Boris Hamanov about 5 years

@deltapie I'm a little confused. The last lshw command correctly shows wla0 as enabled. Are you saying that after the reboot it showed disabled again? Does rfkill still show no wireless?
deltapie about 5 years

Correct, after the reboot it showed disabled again. rfkill shows ID TYPE DEVICE SOFT HARD 0 wlan phy0 unblocked unblocked (thank you again for helping!)
deltapie about 5 years

sudo lshw -C network *-network DISABLED description: Wireless interface
Boris Hamanov about 5 years

@deltapie Please see Update #1 in my answer.
deltapie about 5 years

updated post with screenshot after removing wifi card and replacing back in computer. Still no luck.
deltapie about 5 years

update - downloaded WICD network manager and i'm able to connect to wifi. Very odd. Network Manager issue? Would like to get this working without using wicd.
Boris Hamanov about 5 years

Ok, lets look at syslog. Two different commands. They'll be lengthy, so post them to paste.ubuntu.com and give me the links. grep -i wlan0 /var/log/syslog* and grep -i NetworkManager /var/log/syslog*. (this is a "*" at the end of syslog)
deltapie about 5 years

The first command returned zero results. The second command is pasted in the following location: paste.ubuntu.com/p/vtcrKGfDwt
Boris Hamanov about 5 years

Try a different PCI slot please. Also, please show me rfkill list. Report back.
deltapie about 5 years

No other PCI slot. 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no
Boris Hamanov about 5 years

@deltapie If rfkill unblock wlan0 doesn't work, and wifi settings shows no wifi card, and there's no wifi disable switch or function key... I'd boot to a Ubuntu Live DVD/USB... and if wifi works there... at this point, I'd backup my data and reinstall Ubuntu.
Boris Hamanov about 5 years

@deltapie Please keep me posted, ok?
user56reinstatemonica8 almost 4 years

Also check any 3rd party energy saving software you might have - e.g. I seem to have had this problem less after disabling WiFi disabling options in power profiles in the "Slimbook Energy Preferences" applet
user56reinstatemonica8 almost 4 years

Darn... I have the same problem on 18.04.4...