Ubuntu – Ubuntu 20.04 – No wifi adapter found DELL


I know there are many questions about this, but no one works for me.

I have been more than a week testing blogs, github and forum solutions, actually I really don't know what I have installed, blacklisted and created to try to get back my wifi adapter.

Problem started after I connect my ipad to my laptop.

Manufacturer: Dell Inc.
Product Name: Inspiron 3521

Kernel release:


If I throw this line:

lspci -knn | grep Net -A3; rfkill list


02:00.0 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 modules: bcma, wl
0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no

If I throw this line

sudo modprobe wl


modprobe: FATAL: Module wl not found in directory /lib/modules/5.4.0-37-generic

If I throw this line:

grep wl /etc/modprobe.d/*


/etc/modprobe.d/iwlwifi.conf:# /etc/modprobe.d/iwlwifi.conf
/etc/modprobe.d/iwlwifi.conf:# iwlwifi will dyamically load either iwldvm or iwlmvm depending on the
/etc/modprobe.d/iwlwifi.conf:# microcode file installed on the system.  When removing iwlwifi, first
/etc/modprobe.d/iwlwifi.conf:# remove the iwl?vm module and then iwlwifi.
/etc/modprobe.d/iwlwifi.conf:remove iwlwifi \
/etc/modprobe.d/iwlwifi.conf:(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
/etc/modprobe.d/RTL810xE.conf:options RTL810xE fwlps=N


secure boot disable
load legacy option Enable
Boot list option legacy

Secure Boot not enabled on this system.

if I throw sudo apt install --reinstall bcmwl-kernel-source:

Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.4.0-37-generic/updates/dkms/


DKMS: install completed.
update-initramfs: deferring update (trigger activated)
Processing triggers for man-db (2.9.1-1) ...
Processing triggers for initramfs-tools (0.136ubuntu6) ...
update-initramfs: Generating /boot/initrd.img-5.4.0-37-generic

Anyone could help me?

Best Answer

  • The driver is installed it is shown here:

    Kernel modules: bcma, wl

    wl is the correct driver for this adapter.

    But the problem it is not in use. The reason may be that Secure Boot is enabled in UEFI settings, or it is blacklisted.

    Check if Secure Boot is disabled in UEFI aka BIOS. If that doesn't help, run

    grep wl /etc/modprobe.d/*

    and look if wl is blacklisted somewhere.

    If that doesn't help, reinstall wl by

    sudo apt install --reinstall bcmwl-kernel-source