Madiatek WIFI Card not detected, no wifi [duplicate]

Solution 1:

MEDIATEK Corp. Device [14c3:0608]

This specific pci.id has recently been added to the aliases of the driver mt7921e. Reference: https://www.spinics.net/lists/linux-wireless/msg217303.html

Until this patch reaches a standard Ubuntu kernel, we may, as you've proven, add the pci.id with a udev action. From the terminal:

sudo nano /etc/modprobe.d/mt7921e.conf

Add a single line to this new file:

alias pci:v000014C3d00000608sv*sd*bc*sc*i* mt7921e

Proofread carefully. Save (Ctrl+o followed by Enter) and exit (Ctrl+x followed by Enter) the text editor nano.

Next, do:

sudo nano /etc/udev/rules.d/99-mt7921e.rules

Add a single line:

SUBSYSTEM=="drivers", DEVPATH=="/bus/pci/drivers/mt7921e", ATTR{new_id}="14c3 0608"

Proofread carefully, save and exit as above.

Your wireless should now work as expected. To confirm, please test with a reboot.