One solution is to make an /etc/X11/xorg.conf file which uses a vesa driver.
An example about workable /etc/X11/xorg.conf
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
HorizSync 31.5-67
VertRefresh 50-75
#UseModes "Modes0" #monitor0usemodes
Option "PreferredMode" "1280x1024"
EndSection
Section "Modes"
Identifier "Modes0"
#modes0modeline0
EndSection
Section "Device"
### Available Driver options are:-
### Values: : integer,
###
### [arg]: arg optional
#Option "ShadowFB" # [
#Option "DefaultRefresh" # [
#Option "ModeSetClearScreen" # [
Identifier "Card0"
Driver "vesa" #card0driver
VendorName "Silicon Integrated Systems [SiS]"
BoardName "661/741/760 PCI/AGP or 662/761Gx PCIE VGA Display Adapter"
BusID "PCI:1:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultDepth 16
#Option "metamodes" "1280x1024_60 +0+0" #METAMODES_0
Subsection "Display"
Depth 16
Modes "1280x1024"
EndSubsection
EndSection
If that does not work, delete that file as root or use sudo via tty, where you get pressing ctrl alt f1
sudo rm /etc/X11/xorg.conf
sudo reboot