[CentOS] Centos7 broken after update

I've launch a "yum update" while I was going to lunch. 1 hour later the
system was completely freezed (no mouse, no keyboard, screen black, no
network).

I try a hard reboot => kernel panic on the new kernel

I boot on the old kernel => boot hangs with gnome-shell failure. SSH was
OK so I remove the new kernel and re-install gnome shell.

Reboot is ok but now the computer freeze (no mouse, no keyboard, screen
black) after some time. Yum asks to run  yum-complete-transaction

Running yum-complete-transaction says:

There are 1 outstanding transactions to complete. Finishing the most
recent one
The remaining transaction had 1537 elements left to run

then many package to be removed and start a very long dependances check
and show a lot of errors at the end with a depsolving loop limit reached:

Erreur : Depsolving loop limit reached.
Erreur : Paquet : gtk3-3.22.30-3.el7.i686 (base)
             Requiert : libXext.so.6
             Suppression  : libXext-1.3.3-3.el7.i686 (@base)
                 libXext.so.6
Erreur : Paquet : evolution-mapi-3.28.3-2.el7.x86_64 (base)
             Requiert : libemail-engine.so()(64bit)
             Suppression  : evolution-3.22.6-14.el7.x86_64 (@base)
                 libemail-engine.so()(64bit)
             Suppression  : evolution-3.28.5-2.el7.x86_64 (installed)
                 libemail-engine.so()(64bit)

.......


and then:

 Vous pouvez essayer d'utiliser --skip-broken pour contourner le problème
** 775 problèmes RPMDB préexistants trouvés, la sortie de « yum check »
est la suivante :
GeoIP-1.5.0-13.el7.x86_64 est un doublon de GeoIP-1.5.0-11.el7.x86_64
1:NetworkManager-1.12.0-8.el7_6.x86_64 est un doublon de
1:NetworkManager-1.10.2-16.el7_5.x86_64
1:NetworkManager-glib-1.12.0-8.el7_6.x86_64 des conflits sont installés
NetworkManager-libnm < ('1', '1.12.0', '8.el7_6'):
1:NetworkManager-libnm-1.10.2-16.el7_5.x86_64
1:NetworkManager-glib-1.12.0-8.el7_6.x86_64 est un doublon de
1:NetworkManager-glib-1.10.2-16.el7_5.x86_64
1:NetworkManager-libnm-1.12.0-8.el7_6.x86_64 des conflits sont installés
NetworkManager-glib < ('1', '1.12.0', '8.el7_6'):

...etc and fails.

Any idea to go back to a normal situation before a full re-install ?


Thanks


Patrick