WIFI does not work after new installation 18.04.1

Question

Short version: I downloaded Ubuntu from my Windows PC, made a bootable usb stick and installed it on an Acer Aspire laptop (which had windows before). Now my WIFI does not work and I am completely lost as I need to download everything via Windows PC (But what do I need in this case? As I understand too little I would need to start with random solution like try another Ubuntu version, ...).

Some details after research on the web:

ethtool => not found
ifconfig => not found
lsb_core => not found
iwlist scan
lo       Interface does not support scanning
enp1s0f1 Interface does not support scanning
iwconfig
lo       no wireless extension
enp1s0f1 no wireless extension

I use a "normal installation" and "installed third-party software".

From lshw:
Ethernet interface
RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
Realtek
Name enp1s0f1

As said: I am new to Ubuntu and more information can be shared if I know for what I must look... Any help is highly appreciated!

lspci -nnk | grep 0280 -A3
02:00.0 Network controller [0280]: Broadcom Limited BCM43142 802.11b/g/n [14e4:4365] (rev 01)
        Subsystem: Foxconn International, Inc. BCM43142 802.11b/g/n [105b:07e]
        Kernel modules: wl

lspci -knn | grep Net -A3; rfkill list
0: acer-wireless: Wireless LAN
        Soft blocked: no
        Hard blocked: no
1: acer-bluetooth: Bluetooth
        Soft blocked: no
        Hard blocked: no
2: hci0: Bluetooth
        Soft blocked: no
        Hard blocked: no

Work in progress:

sudo apt install bcmwl-kernel-source
Paketlisten werden gelesen... Fertig
Abhängigkeitsbaum wird aufgebaut.       
Statusinformationen werden eingelesen.... Fertig
bcmwl-kernel-source ist schon die neueste Version (6.30.223.271+bdcom-0ubuntu4).
0 aktualisiert, 0 neu installiert, 0 zu entfernen und 319 nicht aktualisiert.

Let's try to identify your wireless hardware. Please edit your question to add the result of the terminal command: `lspci -nnk | grep 0280 -A3` Welcome to Ask Ubuntu. — chili555, Nov 10 '18 at 14:29
@chili555 It seems `modprobe` does not have an `wl` arg: `modprobe: ERROR: could not insert ´wl´: Required key not available.` I also checked [here](http://manpages.ubuntu.com/manpages/xenial/man8/modprobe.8.html) — Christoph, Nov 10 '18 at 19:43
@chili555 Boot Mode is set to `UEFI` and it seems, I can´t change `secure boot [enabled]`. Do I have to change Boot mode to Legacy? — Christoph, Nov 10 '18 at 21:33
I would first try the mokutil method discussed at the duplicate. — chili555, Nov 10 '18 at 21:57
@chili555 I tried `sudo mokutil --disable-validation` and rebooted - even a shutdown + start. But I was not asked for anything afterwards. How can I check if things really changed? `modprobe` still gives the key not available error. — Christoph, Nov 11 '18 at 19:55
If that doesn't work, then set the BIOS to legacy mode and try modprobe again. — chili555, Nov 12 '18 at 02:36
@chili555: The question is not really a duplicate. 1) You need an Ethernet connection - the ISO-image is not enough. (Is that clear?) 2) Then do the steps described [in your suggetion](https://askubuntu.com/q/762254/891640). 3) Reinstall drivers LAST as discribed [here](https://askubuntu.com/a/60395/891640). It took some time to get this working - I also tried another order 1-3 which did not work(!?). If you like, you can post this as answer - explanations are welcome. I would like to understand what I am doing ;-) — Christoph, Jan 05 '19 at 14:02
I am having difficulty understanding the process you followed. Please write an answer and describe it in detail and then we may discuss it; perhaps in chat. — chili555, Jan 06 '19 at 16:28
@chili555 I think i can't add an answer when the question is marked as duplicate. — Christoph, Jan 06 '19 at 16:32
Please describe your answer in detail here and give me the link: http://paste.ubuntu.com — chili555, Jan 06 '19 at 17:07

WIFI does not work after new installation 18.04.1

0 Answers0