I will try to do videos for you tomorrow it is getting late in the day here ..
a brief synopsis for now .. history: this is standard grub arrangement as "installed by default" used to work flawlessly with multiple partitions of various linux OS's .. It is only since early march that I noticed an issue with newer install disco boots failing .. I have an older disco install on sda1 which has been working all this time through without issues .. upgraded daily .. no alteration of netplan config or i915 module forcing.. I can prevent failures in two different ways .. add the module to /etc/modules or change netplan config to not use NetworkManager as the default.. attached my suspicion is that NetworkManager is crashing the system by running too early as on part of the failure.. the second part is slow loading of the necessary kernal module i915 this may be also the reason the plymouth (busy screen) does not show in the boot phase of the effected partitions which are all recent disco xubuntu spins.. an ubuntu install showed no issues .. wayland only works! When using the freshly installed grub with the partition it belongs to we get the first boot normal every thing works .. but on restarting again (2nd boot) xorg/lightdm initially crash then in about 6 seconds xorg/lightdm restarts ..and works on any other disco-xubuntu partition (except sda1) booting from this fresh grub .. we get the initial crash of xorg/lightdm and a locked system .. no restart of xorg/lightdm at all .. no console either .. only the power switch/ power removal works to reset .. and thus " a very perturbed and frustrated tester " ** Attachment added: "01-netcfg.yaml (password obscured)" https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1821609/+attachment/5256176/+files/01-netcfg.yaml -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1821609 Title: lightdm login screen briefly appears and then blanks out on Intel(R) Core(TM)2 Duo CPU T5870 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1821609/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs