Graphic screen get totaly black

[Alex]

The unity stopped to work at Administrator user.
 I tried to reinstall unity and compiz without success.
Than I created another user, the unity graphics is working properly. I felt the machine loose performance, it was faster before this fail.

The Administrator user I access just by terminal.

Thatś all, not sure how to recover the Administrator unity screen to work properly.

My best guess is that unity is working without laptop screen drivers. The screen driver is VGA. I did not find the VGA driver when I listed all by
Below is the parcial result from LSMW command Drivers check out

 *-display UNCLAIMED

                description: VGA compatible controller

                product: 771/671 PCIE VGA Display Adapter

                vendor: Silicon Integrated Systems [SiS]

                physical id: 0

                bus info: pci@0000:01:00.0

                version: 10

                width: 32 bits

                clock: 66MHz

                capabilities: vga_controller cap_list

                configuration: latency=0

                resources: memory:c0000000-cfffffff memory:d4000000-d401ffff ioport:9000(size=128)

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xorg 1:7.7+1ubuntu8.1
ProcVersionSignature: Ubuntu 3.16.0-70.90~14.04.1-generic 3.16.7-ckt25
Uname: Linux 3.16.0-70-generic x86_64
.tmp.unity.support.test.1:

ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Sat Apr 30 12:52:19 2016
DistUpgraded: Fresh install
DistroCodename: trusty
DistroVariant: ubuntu
ExtraDebuggingInterest: I just need to know a workaround
GraphicsCard:
 Silicon Integrated Systems [SiS] 771/671 PCIE VGA Display Adapter [1039:6351] (rev 10) (prog-if 00 [VGA controller])
   Subsystem: COMPAL Electronics Inc Device [14c0:003a]
InstallationDate: Installed on 2015-05-19 (347 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-70-generic root=UUID=96f56811-f5f4-46bc-aa36-83e88f178a41 ro drm.debug=0xe plymouth:debug
Renderer: Software
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/16/2009
dmi.bios.version: 1.06
dmi.board.name: KSW01
dmi.board.version: REFERENCE
dmi.chassis.type: 10
dmi.chassis.version: N/A
dmi.modalias: dmi:bvn:bvr1.06:bd06/16/2009:svn:pn:pvr:rvn:rnKSW01:rvrREFERENCE:cvn:ct10:cvrN/A:
version.compiz: compiz 1:0.9.11.3+14.04.20150313-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1~ubuntu14.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri N/A
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A
xserver.bootTime: Sat Apr 30 11:42:57 2016
xserver.configfile: default
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.16.0-1ubuntu1.2~trusty2

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Paul White (paulw2u)]

We are sorry that we do not always have the capacity to review all reported bugs in a timely manner. You reported this bug some time ago and there have been many changes in Ubuntu since that time.

Ubuntu 14.04 (trusty) reached end-of-standard-support on April 25, 2019.

Do you still see a problem related to the one that you reported when using a currently supported version of Ubuntu? Please let us know if you do otherwise this report can be left to expire in approximately 60 days time.

Thank you for helping make Ubuntu better.

[Paul White (paulw2u)]

Closing as no response from reporter.