result of xrandr
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 260mm x 140mm
1366x768 60.00*+
1360x768 59.96
1280x720 59.86 60.00 59.74
1024x768 60.00
1024x576 60.00 59.90 59.82
960x540 60.00 59.63 59.82
800x600 60.32 56.25
864x486 60.00 59.92 59.57
640x480 59.94
720x405 59.51 60.00 58.99
680x384 60.00
640x360 59.84 59.32 60.00
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
I'm new to Ubuntu, so i need good instructions. Need help for diagnostic !
Tks in advance