How to restore Grub menu on Ubuntu 16.04?

Question

linux

Hello.
Installed Ubuntu 16.04 LTS. At the very beginning there is no menu where there should be options like "Starting the OS (recovery mod), memtest, etc.
Previously, everything was solved using boot-repair, but now for some reason it does not start on ubuntu 16.04.
How can I solve this problem?

Answer 1

sudo nano /etc/default/grub
set timeout 10
should work