Boot Ubunto into Text Mode

Modify '/etc/default/grub' to replace "quiet splash" with "text" as below:

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="text"
GRUB_CMDLINE_LINUX=""
...

Then run command to make it effective:

sudo update-grub

Reboot to check.