Dell Vostro 5490 no WIFI in Ubuntu 18.04

Please note this:

[    3.205709] iwlwifi 0000:00:14.3: Failed to start RT ucode: -110 
[    3.205711] iwlwifi 0000:00:14.3: Firmware not running - cannot dump error 
[    3.217939] iwlwifi 0000:00:14.3: Failed to run INIT ucode:-110

There are several bug reorts that reference this exact sequence. The first that suggests a fix is this: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1867026 It suggests renaming the firmware file that loads. Please try:

sudo rmmod iwlmvm
sudo rmmod iwlwifi
sudo cp /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode{,.bak}
sudo cp /lib/firmware/iwlwifi-QuZ-a0-jf-b0-48.ucode /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode
sudo modprobe iwlwifi

If this is ineffective, then revert the rename:

sudo rmmod iwlmvm
sudo rmmod iwlwifi
sudo mv /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode{,.bak} /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode
sudo cp /lib/firmware/iwlwifi-Qu-a0-jf-b0-48.ucode /lib/firmware/iwlwifi-Quz-b0-jf-b0-48.ucode
sudo modprobe iwlwifi

Then try the solution here: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1867026/comments/2

Download all the deb files to your desktop. Then install them with:

cd ~/Desktop
sudo dpkg -i linux*.deb

Reboot.