in my yesterday post I mentioned a machine being updated from 18.04 to 20.04. Now this update has finished, but I have no desktop. On booting after the console messages on switch there is only dark screen. With local keyboard I can switch to the other consolescreens (ttyn) and run in text mode. ssh is possible too.
What happened:
during the upgrade process I touched the device. The screen changed to mono colour with 3 vertical bars left, right and nearly midth of monitor. After some time the hartbeat of the device stopped blinking, so I thought nothing would be happening any more.
I stopped the device and started new. Screen was dark now. So I tried to ssh and could login.
running:
$ dpkg --configure -a
$ apt update
$ apt upgrade
$ apt dist-upgrade
allowed to finish the process but some packages were signaled with missing files
fixed by
$ apt reinstall packages
Additionally I issued:
$ apt reinstall lightdm mate
I suppose, the system does switch of the textmode but has no success in starting the graphics mode.
$ sudo lightdm results in a blinking cursor in the upper left corner of the screen
Does that mean, you think of a corrupted filesystem on my drive? And repair means a fsck.
In that case I can try this via alternate computer a the systemdrive is a removeable memory device.
I am not convinced that the problem is a filesystemproblem, but I did a fsck anyhow.
/boot is a FAT-Partition: no errors reported
/ is ext4 an reported as clean
In addition to my original post I have to report that after the
$ sudo lightdm
the system was down after some (short) time.
I had tried to get back to system prompt by hitting ctrl-c; not sure perhaps several times.
So I don't know wether the shutdown was a crash or happened in response to my ctrl-c
Try sudo apt install ubuntu-mate-desktop; I have a hunch that the upgrade went awry and this resulted in all but the most essential packages getting removed, somehow.
thanks for your hint. I can remember I did that long time ago on a x86 machine with some other desktop. A lot of stuff was installed including libraries and applications i.e libre-office. However, this time it did not help, still no graphics desktop after reboot. I checked for syslog entries (before and after the installation), but I did not find an entry clearly marking an error related to my problem.
I've certainly had far more failures exactly like this on upgrades than I have successes, over the years.
Off the top of my head, sudo dpkg-reconfigure lightdm is USUALLY enough to fix them, but I have occasionally had to reinstall all of X as well. I'll check the history on the HTPC in a day or two if you're still struggling then.
I move the systemdisk device to a second hardware of same model. Result was same behavior, so I can be sure not to have a hardware problem with my grafics device
Info:
In about 1 hour I will have guests staying till after 1st Jan 2022. so I don't known wether and when I am able to process new hints.
