no more login screen sddm or lightdm

[alainroger]

hi,
after upgrading on my laptop from kubuntu 17.10 to 18.04, i have no more login screen and this whatever dispaly manager i use (sddm or lightdm).

my laptop have a nvidia video. i tried to remove driver and install oibaf optimized driver, nothing changed.

on my desktop computer that use a radeon rx560 i have the same issue.

while i have a looping login screen on laptop using the lightdm, on my desktop computer with amd radeon i've never reached any login screen neither sddm nor lightdm.

i'm getting crazy as i can only used tablet to check on internet information a nd to post on this forum.

thx a lot for any help.

[omaregb]

I'm having a similar issue, the laptop monitor is not detected so I get a black screen. If I plug in a secondary monitor , I can use it normally and apparently the laptop screen isn't detected at all. I tried swapping drivers and turning on and off the GPU using Nvidia prime. Nothing works, if I go and log in from the console with ctrl alt f4 the text comes up in the laptop screen and the secondary one freezes, I'll try a reinstall tomorrow... I don't know why I never learn, upgrading ALWAYS gives me problems like this

[walttheboss]

I have the same issue. If you/we can write a script that runs after startup that enables the laptop display and disables the external then it may work. I will report back. I have done this before.

[corwin78]

Hello, I have exactly the same problem after upgrade from 17.10 to 18.04 - no DM start, only blinking text cursor.
My laptop is Lenovo ThinkPad W520 with nVidia Quadro 2000M and bloody Optimus of course.

Access to CLI via Alt+Ctrl+F2 is working fine.

What I am tried (and without any positive result) already:
- Reinstall nVidia proprietary driver (recommended version 390)
- Uninstall nVidia proprietary driver and install Nouveau
- Install and set Lightdm
- Switch back to SDDM (via dpkg-reconfigure)

[GreyGeek]

Hello, I have exactly the same problem after upgrade from 17.10 to 18.04 - no DM start, only blinking text cursor.
My laptop is Lenovo ThinkPad W520 with nVidia Quadro 2000M and bloody Optimus of course.

Access to CLI via Alt+Ctrl+F2 is working fine.

What I am tried (and without any positive result) already:
- Reinstall nVidia proprietary driver (recommended version 390)
- Uninstall nVidia proprietary driver and install Nouveau
- Install and set Lightdm
- Switch back to SDDM (via dpkg-reconfigure)

That's an old GPU. The most recent driver I found for it is the 378.12 from last October.

http://www.nvidia.com/Download/drive...x/125399/en-us

Purge any previously installed Nvidia drivers and try this one.

[corwin78]

Thanks for tip, I am removed all nvidia stuff, and installed driver version 375 - unforutnately no success at all, problem remaining without change.

[GreyGeek]

The common thread through all of these problems is one: choosing to upgrade and not do a fresh install. Now, considering all the time each one has used, it would have been much easier to simply save the important data to other mediums, do a fresh install, and restore the data. AND, when doing a fresh install give Kubuntu/Neon the entire drive (as sd1) and when the option to install the filesystem is given, choose Btrfs for the "/" (root) partition and DO NOT create any other partitions, regardless of what you did with other distros. In Btrfs, subvolumes are like partitions. This method of installation will give you two partitions: @ (/) and @home (/home), as shown in the fstab after installation. You can make a backup of @ and @home in seconds and restore in under 5 minutes. IOW, you are never more than 5 minutes away from repairing any problem you encounter. Make snapshots of @ & @home before you shut down every day. If disaster happens and you can boot to a root console you can use btrfs to copy your @bkup to @ and @homebkup to @home and reboot. Keep your last two or three snapshots and delete the rest (using btrfs).

[corwin78]

I dont like such Windows like solution - we are using Linux, so there must be way how to solve it.

[GreyGeek]

Using Btrfs' capabilities isn't a "Windows solution".
But,
purge nvidia, purge lightdm, purge sddm, purge the xorg driver you are using.
and don't forget to delete any config files that purging leaves behind in /etc and /home/.*
Then reboot, reinstall sddm, xorg and plasma-desktop, then reboot.
Then continue your bug hunt.