运行 Ubuntu 16.04 的 Dell XPS 13。启动时，我可以看到显示器通电（从暗变为带背光的暗），但是屏幕上没有任何反应/可见（没有启动消息等）。但是笔记本电脑正常启动，因为我可以登录并会听到确认声音。我还可以连接第二台显示器，它确认系统运行正常。如果我激活两个屏幕，笔记本电脑屏幕将保持暗，带背光。我正在使用英特尔显卡驱动程序。我该如何解决这个问题？
这是 xrandr 的输出：
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 8192 x 8192
eDP-1 connected 1920x1200+1920+0 (normal left inverted right x axis y axis) 294mm x 165mm
3200x1800 59.98 + 47.99
2048x1536 60.00
1920x1440 60.00
1856x1392 60.01
1792x1344 60.01
1920x1200 59.95*
1920x1080 59.93
1600x1200 60.00
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1280x1024 60.02
1440x900 59.89
1280x960 60.00
1360x768 59.80 59.96
1152x864 60.00
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
960x600 60.00
960x540 59.99
800x600 60.00 60.32 56.25
840x525 60.01 59.88
800x512 60.17
700x525 59.98
640x512 60.02
720x450 59.89
640x480 60.00 59.94
680x384 59.80 59.96
576x432 60.06
512x384 60.00
400x300 60.32 56.34
320x240 60.05
DP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
1920x1200 59.95 +
1920x1080 60.00*
1600x1200 60.00
1680x1050 59.88
1280x1024 60.02
1280x960 60.00
1024x768 60.00
800x600 60.32
640x480 59.94
720x400 70.08
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
这是 sudo cat /var/log/Xorg.0.log 的输出：
[ 1614.872] (II) modeset(0): EDID vendor "DEL", prod id 41082
[ 1614.873] (II) modeset(0): Using hsync ranges from config file
[ 1614.873] (II) modeset(0): Using vrefresh ranges from config file
[ 1614.873] (II) modeset(0): Printing DDC gathered Modelines:
[ 1614.873] (II) modeset(0): Modeline "1920x1200"x0.0 154.00 1920 1968 2000 2080 1200 1203 1209 1235 +hsync -vsync (74.0 kHz eP)
[ 1614.873] (II) modeset(0): Modeline "800x600"x0.0 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e)
[ 1614.873] (II) modeset(0): Modeline "640x480"x0.0 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e)
[ 1614.873] (II) modeset(0): Modeline "720x400"x0.0 28.32 720 738 846 900 400 412 414 449 -hsync +vsync (31.5 kHz e)
[ 1614.873] (II) modeset(0): Modeline "1024x768"x0.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e)
[ 1614.873] (II) modeset(0): Modeline "1280x960"x0.0 108.00 1280 1376 1488 1800 960 961 964 1000 +hsync +vsync (60.0 kHz e)
[ 1614.873] (II) modeset(0): Modeline "1280x1024"x0.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e)
[ 1614.873] (II) modeset(0): Modeline "1600x1200"x0.0 162.00 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync (75.0 kHz e)
[ 1614.873] (II) modeset(0): Modeline "1680x1050"x0.0 119.00 1680 1728 1760 1840 1050 1053 1059 1080 +hsync -vsync (64.7 kHz e)
[ 1614.873] (II) modeset(0): Modeline "1920x1080"x60.0 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -hsync +vsync (67.1 kHz e)
[ 1663.155] (II) modeset(0): EDID vendor "DEL", prod id 41082
[ 1663.155] (II) modeset(0): Using hsync ranges from config file
[ 1663.155] (II) modeset(0): Using vrefresh ranges from config file
[ 1663.155] (II) modeset(0): Printing DDC gathered Modelines:
[ 1663.155] (II) modeset(0): Modeline "1920x1200"x0.0 154.00 1920 1968 2000 2080 1200 1203 1209 1235 +hsync -vsync (74.0 kHz eP)
[ 1663.155] (II) modeset(0): Modeline "800x600"x0.0 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e)
[ 1663.155] (II) modeset(0): Modeline "640x480"x0.0 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e)
[ 1663.155] (II) modeset(0): Modeline "720x400"x0.0 28.32 720 738 846 900 400 412 414 449 -hsync +vsync (31.5 kHz e)
[ 1663.155] (II) modeset(0): Modeline "1024x768"x0.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e)
[ 1663.155] (II) modeset(0): Modeline "1280x960"x0.0 108.00 1280 1376 1488 1800 960 961 964 1000 +hsync +vsync (60.0 kHz e)
[ 1663.155] (II) modeset(0): Modeline "1280x1024"x0.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e)
[ 1663.155] (II) modeset(0): Modeline "1600x1200"x0.0 162.00 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync (75.0 kHz e)
[ 1663.155] (II) modeset(0): Modeline "1680x1050"x0.0 119.00 1680 1728 1760 1840 1050 1053 1059 1080 +hsync -vsync (64.7 kHz e)
[ 1663.155] (II) modeset(0): Modeline "1920x1080"x60.0 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -hsync +vsync (67.1 kHz e)