ubuntu启动时声音问题

Question

Ubuntu 第一次启动时，扬声器没有声音。但是当我插入任何耳机时，声音都正常。另外，当我第一次插入耳机并将其从笔记本电脑中弹出时，扬声器的声音也很好。这意味着启动设置有问题。但不幸的是我不知道如何解决这个问题。

我已经尝试过这个：

hamad@hamad-HP-EliteBook-6930p:~$ sudo service pulseaudio restart 
[sudo] password for hamad: 
pulseaudio stop/waiting
pulseaudio start/running, process 3093
hamad@hamad-HP-EliteBook-6930p:~$ sudo service pulseaudio restart 
pulseaudio stop/waiting
pulseaudio start/running, process 3164
hamad@hamad-HP-EliteBook-6930p:~$ pulseaudio -k
hamad@hamad-HP-EliteBook-6930p:~$ sleep 2
hamad@hamad-HP-EliteBook-6930p:~$ pulseaudio
;
^Chamad@hamad-HP-EliteBook-6930p:~$ pulseaudio;
^Chamad@hamad-HP-EliteBook-6930p:~$ pulseaudio -k sleep 2 pulseaudio 
E: [pulseaudio] main.c: Too many arguments.
hamad@hamad-HP-EliteBook-6930p:~$ pulseaudio -k sleep 2
E: [pulseaudio] main.c: Too many arguments.
hamad@hamad-HP-EliteBook-6930p:~$ pulseaudio -k
E: [pulseaudio] main.c: Failed to kill daemon: No such process
hamad@hamad-HP-EliteBook-6930p:~$ sleep 2
hamad@hamad-HP-EliteBook-6930p:~$ pulseaudio