In the case of a laptop, I assume that you are using a wifi link. In that case, it is most unlikely that any connection will be made without the desktop running (since most distributions now use Network Manager, which is normally only enabled when the desktop loads). While it can be run from the command line, its not that easy to do. If it is possible to connect using an ethernet cable, that is more likely to work when you are still in console, though that also may require NM. Can you use a wired link, or are you only able to use wifi?

1 members found this post helpful.

I skimmed through the past posts

I have broken X / X-session manager many times.. but I'm always able to login via console ( ctrl-alt-F2 ) and fix it ( roll back gfx drivers or whatever )

Now I see some mention of a hardware fault
My initial thoughts would be to boot a live usb/dvd and see how far I get with that
If I have a booted live system, I would then explore the file system

an option would be to chroot and update/fix things
This kind of thing you have to make up as you go along

assuming things are simple, and your root file system is on /dev/sda2
using the live system
that would get you logged is a root on the 'real' system
While still in the chroot
you should now be out of the chroot
Assming the LiveUSB did boot you should probably backup any important files.
copy documents to a usb drive, clone a disk drive/partition .. etc.. before messing about too much

Okay, so I used the code recommended by mr mazda to see whether the laptop has access to the internet. I typed "ip a"; this was the result:
...2: enp2so:<BROADCAST, MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 6c:2b:59:33:29:a3 brd ff:ff:ff:ff:ff:ff

Under the first line of the result( 1: ), I saw this:
inet 127.0.0.1/8 scope host lo

Do these results confirm that we have no access to the internet?
And, if so, is it the case that I will require internet access in order to repair my system?

It sounds as though I will need to find an ethernet cable and plug it into my wifi modem somewhere in order to get internet access. I assume there are "how to" guides that will tell me how to use an ethernet cable to connect to the internet.

So, once I get connected to the internet, I assume I will need to go back and try again all of the codes I have already been given, and see whether they will work.

Does this plan sound like the right course of action? Thanks again everyone!!!

you don't have an internet connection

if you can plug in a wire, that will help

if not I can talk you through wifi,
once I get to my laptop and remember how to do it
( its not that hard, I just can't remember the commands off the top of my head )

I am presently trying to get an ethernet cable. I hope that once I am hooked to the internet, that the fixes for my predicament will be easier. I will let you know as soon as I get the ethernet cable. Thanks.

Could you provide the entire output of "ip a"? What you show only shows a single interface, which, from the naming, is most likely a wired NIC. There is no sign in what you posted of any wifi device being found.

While the new naming conventions for devices can be quite strange, most of the ones I've seen use "exxxxx" for wired interfaces and "wxxxxx" for wireless interfaces.

If you can get an ethernet cable, even if it does not automatically connect to the router, it should be quite easy to bring it up and connect it manually.

enpXXsY ( EtherNet Pci No. Slot No. )
wlpXXsY ( WireLess Pci No. Slot No. )

Okay, so I now have the laptop connected to the ethernet modem, but it appears I still do not have internet. I am aasuming this based upon all of the instances of 'failed to fetch' and 'could not resolve'.

In addition, I received 7 errors, only two of which show on my screen:
Err:6 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
Could not resolve 'archive.ubuntu.com'
Err:7 https://repo.skype.com/deb stable InRelease
Could not resolve 'repo.skype.com'
... 198 packages can be upgraded. Run 'apt list --upgradable' to see them.
Failed to fetch http://packages.linuxmint.com/dists/tessa/InRelease Could not resolve 'packages.linuxmint.com'

Any ideas? Thanks

that might be enough to kick'in the networking scripts
with the ip addr we are looking for something that looks like
inet 192.168.0.111/24

if not
if not we can try something else

when you do
sudo ip link set enp2s0 up

look for blinking lights where you plugged the cable in
wait for them to slow down before the second ip addr
( should only be a few seconds )

First, assuming you don't have an internet connection isn't much help. You need to be sure. So please enter the following commands and post ALL of the output (and PLEASE, use code tags - it makes it much easier to read the returns):

If, as you suspect you don't have an internet connection, you'll have to make it manually. But first, make sure that you don't. I can take you through the steps necessary to connect to the router, but lets make sure that is what is needed first.

I realize that you want me to post everything that I see on the screen, and not to leave anything out. I am prepared to do that, but I have posted much of what I see, and to type an entire screen full of results would take me twenty minutes and it would ultimately yield the same results
Also, I looked up code tags on the internet and after reading four articles, I still don't know what they are. If it is helpful, I can post all of my screen 'results' in these <>?

I will start with the 3 lines of code recommended by Firerat:
ip addr
sudo ip link set enp2s0 up
ip addr

I assume that each of these lines has to be entered individually, and that there is no way to enter 3 lines of text as three lines, as each line requires its own Return.
So I entered the first line: ip addr
The result I got was identical to the result I received in Post #33, when I had typed 'ip a'.
Next I entered the second line: 'sudo ip link set enp2s0 up'
The result was absolutely nothing.
Then I entered the 3rd and final line of code, which was the same as the first, and rather predictably it gave me the same result as the first line of code had. (See post 33)
Then I entered 'sudo service networking restart'.
The result was absolutely nothing.

If we need networking, shouldn't I try selecting "network - Enable networking" from the Recovery Menu? Nobody has suggested this yet, possibly because it was not yet established (way back when) that I had no internet capability.

Anyway, I went ahead and selected "Enable networking" and one result I saw was this:
...<3: inet 192.168.0.7/24>
and also <inet6 fe80::8286:c51e:92dd:d6f/64

After seemingly getting internet, I went ahead and tried sudo apt update.
After an apparently successful update, with no error messages, I tried to reboot the laptop, but it still won't boot.
Should I now go back thru this thread and try all the advice, in sequential order, again? Perhaps some of those suggestions will work this time. It does seem we are back to dealing with the bad display manager again.

Apt update only prepares for upgrading. Now you need:

yeap, if you are doing recovery that would involve needing networking enabled it makes sense to use the enable networking option.
I didn't know it was an option.

If you hit the quote button you can see how we do [c0de]code tags[/c0de]
that is two commands on one line, the && is special here
it means that the shell only proceeds to the right if the command on the left does not return an error.
And yes, they were intended to be one at a time, a before and after to see if there was a change

Once you have all the updates* done, we hope that lightdm is back up and running
If not , well, lets cross that bridge later**

* which we should really refer to as upgrades and not updates.... I will try, but habits are hard to break
** I'm thinking --reinstall lightdm, or switch to sddm ( gdm3 if no sddm )

After successfully (?) reinstalling my lightdm, my laptop will still not reboot. Consequently, I took it upon my newbie self to finally understand just how to use pastebin. I never even understood it was a program. Well, now I do and I've created multiple pastebin files/pages for all to see and hopefully they might help us to figure out what is wrong.

So, without further ado:
journalctl -b > pastebin.com/TyUxC4Wd
sudo apt update > zA5Ccsub
sudo apt upgrade > JXn0bRhz
dmesg > 4XqkXfde
apt-get install --reinstall ligtdm > g0iTDRki

When I typed 'apt-get install --reinstall lightdm', the response I got seemed as though it worked: "get...fetched...reading...unpacking ...setting up lightdm... processing triggers...

After it appeared to be finished, I rebooted, but still had a blank screen after 10 minutes

Next I tried 'dpkg-reconfigure lightdm' and again rebooted, and stared at a blank screen for 15 minutes.
Is there a way that I can test my lightdm to see that it is working properly? I believe hazel had stated in an earlier post that lightdm failures are linked to a specific hardware failure.

I will next try the Code: 'systemctl - n999 status lightdm' in hopes we can learn whether the lightdm is still the problem.

In any case, I am hoping that the pastebinit files will be of some help in figuring this out.
Thanks all!!!