Edit: now solved. See answer below, but I cannot accept it until two days hence.
My system (Laptop Dell Inspiron 15 7000 series 7548, dual boot Windows 10 & Xubuntu 16.04) has become unusable after installing a regular update (ubuntu base) via the software updater on my Xubuntu 16.04 system. The system does boot, but on first inspection, these are the problems:
1) mouse cursor is frozen
2) no network connection. sudo service network-manager restart does not solve the issue
3) Resolution has reset from 1920x1080 to native 3848X2160, making troubleshooting difficult (15.6' laptop screen)
While troubleshooting individual issues I have discovered that:
ifconfig -a just shows 'lo' but neither eth0 nor wlan0
/etc/modules does not list ANY modules to be loaded on boot
Manually adding psmouse and iwlwifi does not solve anything
Trying to run recovery mode (via GRUB boot) I get an error ' [FAILED] failed to load kernel modules'
Trying to either enable networking in recovery mode or repair packages results in graphical glitches with lines of terminal code (usually displayed during boot, of the style [ OK/FAILED ] < whatever it was loading > covering my screen in this fashion:
Example code Example code Example code
Recovery mode also calculates the pixels on my screen wrong, meaning I can NOT see the current line of the terminal (although I can guess in some cases).
This is what I currently can do/acces to troubleshoot: - I can boot onto Xubuntu desktop and run applications/terminals with keyboard only. - I can open a terminal with cntl-alt-F2.
If anyone knows how to start solving this, other than creating a fresh install, I would be most grateful. Please keep in mind I am not a very experienced user, so patient, detailed instructions would be very much appreciated.
When requesting info/offering solutions, please keep in mind that: - I cannot copy/paste from linux to windows (where I am posting this from) and have to reboot to check anything, so logs etc I will have to photograph or type. - My laptop does NOT have an ethernet port. I have internetaccess in winwdows and can download things there, but cannot connect to wired internet under linux.
Thanks very much!