Partial upgrade couldn't be completed

Yesterday, i was doing my upgrade to 8.10 through the Update manager, but i failed due to the lake of repositories, though i did it through terminal using these commends;

sudo apt-get install update-manager-core ,
Prompt=normal ,
sudo do-release-upgrade.

but now when i tried to use the update manager after that, a partial upgrade window appears, and when i accepted to do the updates.. then system began those updates for a while, then disappeared suddenly without completing the upgrade.. no matter how many times i repeat it..

How could i solve this problem?

Thanks in advance everyone..