我已经安装了 ubuntu 17.10 和 16.0，但启动时有时会突然闪烁。我尝试过很多方法修复它，比如这个
1. check the file system on your Ubuntu partition...
boot to the GRUB menu
choose Advanced Options
choose Recovery mode
choose Root access
at the # prompt, type sudo fsck -f /
repeat the fsck command if there were errors
type reboot
更新＃1：
boot to the GRUB menu
select Ubuntu
hit the e key
use arrow keys to move
find the line that has "quiet splash"
add nomodeset, so "quiet splash nomodeset"
hit F10 to exit and continue boot
see if it flickers
但问题仍然存在，发生了什么？我该如何修复它？