No WiFi nor Ethernet connection on Dell Inspiron/ubuntu 18.04.3

Question

I am using Ubuntu 18.04 on a Dell Inspiron. After updating I found myself with no WiFi adapter installed. I tried to restore the WiFi adapter by running this script I found on GitHub.

#!/bin/bash

printf "
Powered by:
  ___  _      ___  _      
 | _ \(_) __ | __|(_)__ __
 |   /| |/ _|| _| | |\ \ /
 |_|_\|_|\__||_|  |_|/_\_\
"
echo""
sudo cd /tmp/
sudo wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.1/linux-headers-5.1.0-050100_5.1.0-050100.201905052130_all.deb
sudo wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.1/linux-headers-5.1.0-050100-generic_5.1.0-050100.201905052130_amd64.deb
sudo wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.1/linux-image-unsigned-5.1.0-050100-generic_5.1.0-050100.201905052130_amd64.deb
sudo wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.1/linux-modules-5.1.0-050100-generic_5.1.0-050100.201905052130_amd64.deb
sudo dpkg -i *.deb

#Wifi drive install
sudo wget https://wireless.wiki.kernel.org/_media/en/users/drivers/iwlwifi/iwlwifi-cc-46.3cfab8da.0.tgz
sudo tar -xzvf iwlwifi-cc-46.3cfab8da.0.tgz
sudo cp iwlwifi-cc-46.3cfab8da.0/iwlwifi-cc-a0-46.ucode /lib/firmware/
echo "Please Reboot your pc"
~   

After rebooting (as prompted to do once the script was executed), the wired connection sign disappeared from the taskbar as well. I opened the system settings/network connections and got this:

It seems I do have a connection but still no working internet connection!!!

Output of the Wireless Script:

########## wireless info START ##########

Report from: 10 Nov 2019 13:57 EET +0200

Booted last: 10 Nov 2019 00:00 EET +0200

Script from: 22 Oct 2018 03:34 UTC +0000

##### release ###########################

Distributor ID: Ubuntu
Description:    Ubuntu 18.04.3 LTS
Release:    18.04
Codename:   bionic

##### kernel ############################

Linux 5.1.0-050100-generic #201905052130 SMP Mon May 6 01:32:59 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Parameters: ro, quiet, splash, vt.handoff=1

##### desktop ###########################

Unity

##### lspci #############################

06:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n [14e4:4365] (rev 01)
    Subsystem: Dell Wireless 1704 802.11n + BT 4.0 [1028:0016]
    Kernel driver in use: bcma-pci-bridge

07:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL810xE PCI Express Fast Ethernet controller [10ec:8136] (rev 07)
    Subsystem: Dell RTL810xE PCI Express Fast Ethernet controller [1028:0655]
    Kernel driver in use: r8169

##### lsusb #############################

Bus 001 Device 007: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 006: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0
Bus 001 Device 004: ID 0c45:670b Microdia 
Bus 001 Device 005: ID 045e:0084 Microsoft Corp. Basic Optical Mouse
Bus 001 Device 009: ID 0930:6545 Toshiba Corp. Kingston DataTraveler 102/2.0 / HEMA Flash Drive 2 GB / PNY Attache 4GB Stick
Bus 001 Device 003: ID 05e3:0608 Genesys Logic, Inc. Hub
Bus 001 Device 002: ID 8087:8001 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 002: ID 03f0:e111 Hewlett-Packard 
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

##### PCMCIA card info ##################

##### rfkill ############################

0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no

##### secure boot #######################

'mokutil' is not installed (package "mokutil").

##### lsmod #############################

dell_laptop            20480  0
ledtrig_audio          16384  3 snd_hda_codec_generic,snd_hda_codec_realtek,dell_laptop
dell_wmi               20480  0
dell_smbios            28672  2 dell_wmi,dell_laptop
dell_wmi_descriptor    20480  2 dell_wmi,dell_smbios
sparse_keymap          16384  1 dell_wmi
mxm_wmi                16384  1 nouveau
wmi_bmof               16384  0
bcma                   61440  0
wmi                    32768  6 dell_wmi,wmi_bmof,dell_smbios,dell_wmi_descriptor,mxm_wmi,nouveau
video                  45056  4 dell_wmi,dell_laptop,i915,nouveau

##### interfaces ########################

[/etc/network/interfaces]
auto lo
iface lo inet loopback

##### ifconfig ##########################

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback <MAC address> brd <MAC address>
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether <MAC 'enp7s0' [IF1]> brd <MAC address>
    inet 192.168.1.2/24 brd 192.168.1.255 scope global dynamic enp7s0
       valid_lft 84452sec preferred_lft 84452sec
    inet6 2a02:2149:8419:a900:48c4:2602:bb11:a9e2/64 scope global temporary dynamic 
       valid_lft 86354sec preferred_lft 43154sec
    inet6 2a02:2149:8419:a900:929a:f7a2:5cd3:f74f/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 86354sec preferred_lft 43154sec
    inet6 fe80::b2aa:4781:308f:8281/64 scope link 
       valid_lft forever preferred_lft forever

##### iwconfig ##########################

enp7s0    no wireless extensions.

lo        no wireless extensions.

##### route #############################

default via 192.168.1.1 dev enp7s0 proto static metric 100 
192.168.1.0/24 dev enp7s0 proto kernel scope link src 192.168.1.2 metric 100 

##### resolv.conf #######################

[777 root '/etc/resolv.conf' -> '../run/systemd/resolve/stub-resolv.conf']

nameserver 127.0.0.53
options edns0

##### network managers ##################

Installed:

    None found.

Running:

root      1159     1  0 13:24 ?        00:00:00 /snap/network-manager/379/usr/sbin/NetworkManager --config-dir=/var/snap/network-manager/379/conf.d/ --config=/snap/network-manager/379/etc/NetworkManager/NetworkManager.conf --log-level=INFO --no-daemon

##### NetworkManager info ###############

NetworkManager is not installed (package "network-manager").

##### NetworkManager.state ##############

cat: /var/lib/NetworkManager/NetworkManager.state: No such file or directory

##### NetworkManager config #############

[[/usr/lib/NetworkManager/conf.d/no-mac-addr-change.conf]]
[device-mac-addr-change-wifi]
match-device=driver:rtl8723bs,driver:rtl8189es,driver:r8188eu,driver:8188eu,driver:eagle_sdio,driver:wl
wifi.scan-rand-mac-address=no
wifi.cloned-mac-address=preserve
ethernet.cloned-mac-address=preserve

##### NetworkManager profiles ###########

##### Netplan config ####################

[/etc/netplan/01-network-manager-all.yaml]
network:
  version: 2
  renderer: NetworkManager

##### iw reg get ########################

Region: Europe/Athens (based on set time zone)

global
country 00: DFS-UNSET
    (2402 - 2472 @ 40), (6, 20), (N/A)
    (2457 - 2482 @ 20), (6, 20), (N/A), AUTO-BW, PASSIVE-SCAN
    (2474 - 2494 @ 20), (6, 20), (N/A), NO-OFDM, PASSIVE-SCAN
    (5170 - 5250 @ 80), (6, 20), (N/A), AUTO-BW, PASSIVE-SCAN
    (5250 - 5330 @ 80), (6, 20), (0 ms), DFS, AUTO-BW, PASSIVE-SCAN
    (5490 - 5730 @ 160), (6, 20), (0 ms), DFS, PASSIVE-SCAN
    (5735 - 5835 @ 80), (6, 20), (N/A), PASSIVE-SCAN
    (57240 - 63720 @ 2160), (N/A, 0), (N/A)

##### iwlist channels ###################

enp7s0    no frequency information.

lo        no frequency information.

##### iwlist scan #######################

enp7s0    Interface doesn't support scanning.

lo        Interface doesn't support scanning.

##### module infos ######################

[bcma]
filename:       /lib/modules/5.1.0-050100-generic/kernel/drivers/bcma/bcma.ko
license:        GPL
description:    Broadcom's specific AMBA driver
srcversion:     9FF0F781F456EC613F149E3
depends:        
retpoline:      Y
intree:         Y
name:           bcma
vermagic:       5.1.0-050100-generic SMP mod_unload 
signat:         PKCS#7
signer:         
sig_key:        
sig_hashalgo:   md4

##### module parameters #################

##### /etc/modules ######################

##### modprobe options ##################

[/etc/modprobe.d/amd64-microcode-blacklist.conf]
blacklist microcode

[/etc/modprobe.d/blacklist-ath_pci.conf]
blacklist ath_pci

[/etc/modprobe.d/blacklist.conf]
blacklist evbug
blacklist usbmouse
blacklist usbkbd
blacklist eepro100
blacklist de4x5
blacklist eth1394
blacklist snd_intel8x0m
blacklist snd_aw2
blacklist i2c_i801
blacklist prism54
blacklist bcm43xx
blacklist garmin_gps
blacklist asus_acpi
blacklist snd_pcsp
blacklist pcspkr
blacklist amd76x_edac

[/etc/modprobe.d/blacklist-rare-network.conf]
alias net-pf-3 off
alias net-pf-6 off
alias net-pf-9 off
alias net-pf-11 off
alias net-pf-12 off
alias net-pf-19 off
alias net-pf-21 off
alias net-pf-36 off

[/etc/modprobe.d/intel-microcode-blacklist.conf]
blacklist microcode

[/etc/modprobe.d/iwlwifi.conf]
remove iwlwifi \
(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
&& /sbin/modprobe -r mac80211

##### rc.local ##########################

grep: /etc/rc.local: No such file or directory

##### pm-utils ##########################

##### udev rules ########################

[/etc/udev/rules.d/70-snap.network-manager.rules]
# network-manager
KERNEL=="rfkill", TAG+="snap_network-manager_networkmanager"
# ppp
KERNEL=="ppp", TAG+="snap_network-manager_networkmanager"
# ppp
KERNEL=="tty[a-zA-Z]*[0-9]*", TAG+="snap_network-manager_networkmanager"
TAG=="snap_network-manager_networkmanager", RUN+="/usr/lib/snapd/snap-device-helper $env{ACTION} snap_network-manager_networkmanager $devpath $major:$minor"

##### dmesg #############################

[   63.488988] r8169 0000:07:00.0 enp7s0: Link is Down
[   65.245800] r8169 0000:07:00.0 enp7s0: Link is Up - 100Mbps/Full - flow control rx/tx
[   65.245810] IPv6: ADDRCONF(NETDEV_CHANGE): enp7s0: link becomes ready

########## wireless info END ############

Answer 1

I dealt with the same problem. Try this:

1. disable Secure Boot in UEFI (BIOS) settings

2. reinstall linux firmware sudo apt install linux-firmware

3. add in grub the parameter pcie_aspm=off :

   sudo gedit /etc/default/grub

   Add pcie_aspm=off to the GRUB_CMDLINE_LINUX_DEFAULT

4. reboot

It worked for me, Good luck!

Answer 2

1- Go to Software & Updates, and then go to additional drivers tab. Within that tab select the driver for the WiFi adapter. Finally, apply changes.

2- After sound that you need to update the drivers. You can go through updates via GUI but the best way is using the command line:

sudo apt update
sudo apt  --reinstall install bcmwl-kernel-source

3- Finally, you have to disable the secure boot from your BIOS. The way to do that depends on your laptop/pc. Usually F2 or F3 let you access the BIOS setup and there you have to search for the secure boot option and disable it.

4- Reboot and (hopefully) enjoy.