Scinetific linux GUI doesn't start

I am a new user of scientific linux 6 .

I am working on a project started by others and Unfortunatly , the GUI stopped working.

I need to find out how to trouble shoot the GUI to solve the problem .

What I have now When I open my PC is a complete black terminal .

I need to go back to the GUI and start troubleshooting.

Can somebody advice me how to start ?

I Did

#yum update.

#Xorg -configure : gives the error ( Missing output drivers. Configuration failed )

I tried also

#xinit : it gives errors ( no screens found )

#lspci اgrep VGA

( 00:02.0 VGA compatible controller : Intel Corporation Xeon E3 v3/4th Gen Core Processor Integrated Graphics controller ( rev 06)

#ls /usr/lib/xorg/modules/drivers

( ls : cannot access /usr/lib/xorg/modules/drivers : No such file or directory )

#startx

[[[

(==) Log file: "/var/log/Xorg.0.log", Time: Mon Apr 27 16:32:29 2015

(==) Using Config file : "/etc/X11/xorg.conf"

(==) Using system Config directory "/usr/share/X11/xorg.conf.d"

Initializing built-in extension Generic Event Extension

Initializing

...

..

.... ( NOTE : ... refers to lines Initializing built in , but I am un able to copy paste as I am using another computer to log onto the internet , If you think they are important to be posted here , I would write them

(EE)

Fatal server error :

(EE) no screens found(EE)

(EE)

Please consult the Scientific linux support at http://www.scientificlinux.org/maillists for help .

(EE) Please also check the log file at " /var/log/Xorg.0.log" for additional information.

(EE)

(EE) Server terminated with error (1). Closing log file .

giving up.

xinit: Connection refused ( errno 111) : unable to connect to Xserver

xinit: No Such process (errno 3) : Server error.

[[]

#Xorg -configure

[[[

X.Org X server 1.15.0

Release Date:

Xprotocol Version 11, Revision 0

Build Operating System: s16 2.6.32-504.e16.x86_64

Current operating System : Linux master.fci 2.6.32-504.e16.x86_64 #1 SMP Tue jan 27 13;39;10 CST 2015 x86-64

Kernel Command line: ro root=/dev/mapper/vg_master-lv_root rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 rd_NO_MD

rg_LVM_LV=vg_master/lv_swap SYSFONT=latarcyrheb=sun16 rd_LVM_LV=vg_master/lv_root rd_NO_DM rd_NO_DM rhgb quiet crashkernel=131M@0M

Build Date: 11 December 2014 01:54:26PM

Build ID : xorg-X11-server 1.15.0-25.s16

Current version of pixman: 0.32.4

Before reporting problems , check http://www.scientificlinux.org/maillists

to make sure that you have the latest version

Markers: (--)probed, (**)from config file, (==) default setting,

(++)from command line , (!!)notice, (II) informational ,

(WW) warning, (EE) error, (NI) not implemented , (??) unknown.

(==) Log file: "/var/log/Xorg.0.log", Time: Mon Apr 27 16:49:53 2015

Missing output drivers. Configuration failed

(EE) Server terminated with error (2). Closing log file.

[[]

#nano /etc/xorg.conf.new

[ opens an empty file ]

Any ideas how to get the gui to work again ?

Thanks