i can not start x server from cli mode.how to solve
First you might want to take a look at the X server logs. On my systems that's typically in /var/log/Xorg.[display number].log. I would assume for you that if you type:
less /var/log/Xorg.0.log
or
less /var/log/XFree86.0.log
And then page to the end of the log file you might find something useful to report back here.