15.10 to 16.04 Upgrade installation interrupted

Question

During the upgrading installation from 15.10 to 16.04.1 the power went off, now the computer cannot launch the OS, so I cannot do anything. What can I do? Thank you in advance for your help

Answer 1

Try this:

A. Boot your PC with the Ubuntu Live DVD/USB.

B. Open a terminal,

Press Ctrl+Alt+T

C. Use fdisk utility to list the partitions on a hard drive.

    sudo fdisk -l

Suppose it informs that / is /dev/sda1, continue running:

sudo umount /dev/sda1
sudo fsck -y /dev/sda1
sudo mount /dev/sda1 /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /dev/pts /mnt/dev/pts
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo chroot /mnt
nano /etc/resolv.conf

In the open file paste these lines:

nameserver 208.67.222.222
nameserver 208.67.220.220

Ctrl+O Save File

Ctrl+X Close nano

Continue running:

nano /etc/apt/sources.list

In the open file delete content and paste these lines:

deb http://archive.ubuntu.com/ubuntu/ xenial main universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ xenial-security multiverse main universe restricted
deb http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse main universe restricted
deb http://archive.ubuntu.com/ubuntu/ xenial-backports multiverse main universe restricted
deb http://archive.canonical.com/ubuntu xenial partner

Ctrl+O Save File

Ctrl+X Close nano

Continue running:

dpkg --configure -a
apt-get -f install
apt-get -m install
apt-get update
apt-get install --reinstall ubuntu-desktop
apt-get dist-upgrade
apt-get autoremove
apt-get clean
exit
sudo reboot

Answer 2

You must make sure everything is intact. Without knowing more specifics, I suggest reinstalling the boot loader. Possibly a file that is involved in the boot process had been corrupted. First, boot into a live disk, mount your installation, chroot into it, and try to reinstall grub with "grub-install"