I just installed Ubuntu 16.04 on a Compaq Presario CQ57 laptop (came out around 2012). The machine has a Realtek RTL8188CE wifi adapter. It's still going strong! However, now that I've switched to Ubuntu the wifi is not working. The wifi discovery button on the keyboard is always red, even if I press it. And when I turn on "Enable Wi-Fi" in the network settings under Wi-Fi Networks "Wi-Fi is disabled" is shown in grey. I'm stumped.
UPDATE: I just got a USB wifi adapter to try. The laptop recognizes it, but won't let me turn it on via command line or GUI. In the GUI I click the on/off switch to "on" and it instantly returns to "off". So strange.
First I followed all the suggestions on this similar question post Can't view Wifi networks after upgrading to Ubuntu 16.04.
lo no wireless extensions. wlo1 IEEE 802.11bgn ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=off Retry short limit:7 RTS thr=2347 B Fragment thr:off Power Management:on eno1 no wireless extensions.
lo Interface doesn't support scanning. wlo1 Failed to read scan data : Network is down eno1 Interface doesn't support scanning.
service network-manager restart, ethernet disconnected but still could not activate wifi.
sudo rfkill list:
0: phy0: Wireless LAN Soft blocked: no Hard blocked: yes 1: hp-wifi: Wireless LAN Soft blocked: yes Hard blocked: yes
So then I tried:
sudo ifconfig wlp4s0 up service network-manager restart
wifi is still disabled...
I then went into the BIOs and could not find Secure Boot (to turn it off). I did find Boot Order, and enabled the Network Adapter to power on at boot.
bcmwl-kernel-source sudo apt-get purge bcmwl-kernel-source sudo apt-get install linux-generic bcmwl-kernel-source reboot
EDIT: I purged bcmwl-kernel-source by recommendation.
I followed the similar AskUbuntu question over here Wireless not working on Toshiba Satellite C55-A5281 answer by @chili555, and installed some headers with
sudo apt-get install linux-headers-generic build-essential, all of which were already installed and up to date. Then I downloaded a backport from 07/30/2013 and unzipped it.
Generating local configuration database from kernel....kernel version parse failed! Makefile:40: recipe for target 'defconfig-rtlwifi' failed make: ***[defconfig-rtlwifi] Error 1
So now I'm stuck again. Should I download another backport or try something else?