我无法通过 HDMI 将 Ubuntu 13.10 盒子连接到 55 英寸 LG LED 1080p 240 HZ 智能电视（型号 #55LAS400）。有时电视上只显示绿屏，有时根本无法识别电视。
通过 HDMI 或 VGA 连接到 ASUS 显示器没有问题，所以我知道电缆没有问题。我使用的是 ATI Radeon 5450 HD 显卡，这个问题在开源 X.Org 和 fglrx catalyst 驱动程序上都出现了。
Ubuntu wiki 上的 HDMI 页面讨论电视 HDMI 模式线出现故障。我尝试了 DVI 方法：
如果您的电视有单独的 DVI 端口，您可以尝试连接到该端口（尝试用 HDMI->DVI 电缆替换 HDMI->HDMI 电缆，将 DVI 端连接到电视，将 HDMI 连接到计算机）。如果您能够在那里获得有效信号，请记下其模式线并尝试使用 HDMI->HDMI 连接。通过 DVI，电视有时会报告视频驱动程序可以处理的非隔行原始分辨率。
这是当 HDMI（HDMI-0）和 VGA（VGA-0）都连接到 LG 电视但电视使用 VGA 输入时“xrandr --verbose”的输出。在此配置中，电视甚至无法识别 HDMI 输入，但 Ubuntu 可以识别已连接的 HDMI-0。
steambox@steambox-MS-7786:~$ xrandr --verbose
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
HDMI-0 connected (normal left inverted right x axis y axis)
Identifier: 0x53
Timestamp: 3054999
Subpixel: horizontal rgb
Clones:
CRTCs: 0 1 2 3
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
EDID:
00ffffffffffff001e6d010001010101
0116010380a05a780aee91a3544c9926
0f5054a1080031404540614071408180
010101010101023a801871382d40582c
4500a05a0000001e662150b051001b30
40703600a05a0000001e000000fd003a
3e1e5310000a202020202020000000fc
004c472054560a202020202020200143
02032ef1489022200504030201230957
0778030c004000802d20c00e014f00fe
08100610181028103810e3050301023a
801871382d40582c4500a05a0000001e
011d8018711c1620582c2500a05a0000
009e011d007251d01e206e285500a05a
0000001e263680a070381f4030202500
a05a0000001a00000000000000000034
underscan vborder: 0
range: (0, 128)
underscan hborder: 0
range: (0, 128)
underscan: off
supported: offonauto
coherent: 1
range: (0, 1)
1920x1080 (0x57) 148.5MHz +HSync +VSync +preferred
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.5KHz
v: height 1080 start 1084 end 1089 total 1125 clock 60.0Hz
1920x1080 (0x59) 148.4MHz +HSync +VSync
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.4KHz
v: height 1080 start 1084 end 1089 total 1125 clock 59.9Hz
1920x1080 (0x2ed) 138.6MHz +HSync -VSync
h: width 1920 start 1968 end 2000 total 2080 skew 0 clock 66.6KHz
v: height 1080 start 1082 end 1087 total 1111 clock 60.0Hz
1920x1080i (0x5a) 74.2MHz +HSync +VSync Interlace
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 33.8KHz
v: height 1080 start 1084 end 1094 total 1125 clock 60.1Hz
1920x1080 (0x2ee) 74.2MHz +HSync +VSync
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 33.8KHz
v: height 1080 start 1084 end 1089 total 1125 clock 30.0Hz
1920x1080 (0x2ef) 74.2MHz +HSync +VSync
h: width 1920 start 2558 end 2602 total 2750 skew 0 clock 27.0KHz
v: height 1080 start 1084 end 1089 total 1125 clock 24.0Hz
1920x1080i (0x5c) 74.2MHz +HSync +VSync Interlace
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 33.7KHz
v: height 1080 start 1084 end 1094 total 1125 clock 60.0Hz
1920x1080 (0x2f0) 74.2MHz +HSync +VSync
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 33.7KHz
v: height 1080 start 1084 end 1089 total 1125 clock 30.0Hz
1920x1080 (0x2f1) 74.2MHz +HSync +VSync
h: width 1920 start 2558 end 2602 total 2750 skew 0 clock 27.0KHz
v: height 1080 start 1084 end 1089 total 1125 clock 24.0Hz
1280x1024 (0x5f) 108.0MHz +HSync +VSync
h: width 1280 start 1328 end 1440 total 1688 skew 0 clock 64.0KHz
v: height 1024 start 1025 end 1028 total 1066 clock 60.0Hz
1360x768 (0x2f2) 85.5MHz +HSync +VSync
h: width 1360 start 1424 end 1536 total 1792 skew 0 clock 47.7KHz
v: height 768 start 771 end 777 total 795 clock 60.0Hz
1152x864 (0x2f3) 81.6MHz -HSync +VSync
h: width 1152 start 1216 end 1336 total 1520 skew 0 clock 53.7KHz
v: height 864 start 865 end 868 total 895 clock 60.0Hz
1280x720 (0x64) 74.2MHz +HSync +VSync
h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 45.0KHz
v: height 720 start 725 end 730 total 750 clock 60.0Hz
1280x720 (0x66) 74.2MHz +HSync +VSync
h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 45.0KHz
v: height 720 start 725 end 730 total 750 clock 59.9Hz
1024x768 (0x6a) 65.0MHz -HSync -VSync
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
v: height 768 start 771 end 777 total 806 clock 60.0Hz
800x600 (0x70) 40.0MHz +HSync +VSync
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
v: height 600 start 601 end 605 total 628 clock 60.3Hz
720x480 (0x73) 27.0MHz -HSync -VSync
h: width 720 start 736 end 798 total 858 skew 0 clock 31.5KHz
v: height 480 start 489 end 495 total 525 clock 60.0Hz
720x480 (0x74) 27.0MHz -HSync -VSync
h: width 720 start 736 end 798 total 858 skew 0 clock 31.5KHz
v: height 480 start 489 end 495 total 525 clock 59.9Hz
640x480 (0x77) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 490 end 492 total 525 clock 60.0Hz
640x480 (0x2f4) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 489 end 492 total 525 clock 59.9Hz
640x480 (0x78) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 490 end 492 total 525 clock 59.9Hz
720x400 (0x79) 28.3MHz -HSync +VSync
h: width 720 start 738 end 846 total 900 skew 0 clock 31.5KHz
v: height 400 start 412 end 414 total 449 clock 70.1Hz
DVI-0 disconnected (normal left inverted right x axis y axis)
Identifier: 0x54
Timestamp: 3054999
Subpixel: horizontal rgb
Clones:
CRTCs: 0 1 2 3
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
load detection: 1
range: (0, 1)
underscan vborder: 0
range: (0, 128)
underscan hborder: 0
range: (0, 128)
underscan: off
supported: offonauto
coherent: 1
range: (0, 1)
VGA-0 connected 1920x1080+0+0 (0x57) normal (normal left inverted right x axis y axis) 160mm x 90mm
Identifier: 0x55
Timestamp: 3054999
Subpixel: no subpixels
Gamma: 1.0:1.0:1.0
Brightness: 1.0
Clones:
CRTC: 0
CRTCs: 0 1 2 3
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
EDID:
00ffffffffffff001e6d010001010101
0116010368a05a780aee91a3544c9926
0f5054a1080031404540614071408180
010101010101023a801871382d40582c
4500a05a0000001e662150b051001b30
40703600a05a0000001e000000fd003a
3e1e5310000a202020202020000000fc
004c472054560a20202020202020005c
load detection: 1
range: (0, 1)
1920x1080 (0x57) 148.5MHz +HSync +VSync *current +preferred
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.5KHz
v: height 1080 start 1084 end 1089 total 1125 clock 60.0Hz
1280x1024 (0x5f) 108.0MHz +HSync +VSync
h: width 1280 start 1328 end 1440 total 1688 skew 0 clock 64.0KHz
v: height 1024 start 1025 end 1028 total 1066 clock 60.0Hz
1360x768 (0x2f2) 85.5MHz +HSync +VSync
h: width 1360 start 1424 end 1536 total 1792 skew 0 clock 47.7KHz
v: height 768 start 771 end 777 total 795 clock 60.0Hz
1152x864 (0x2f3) 81.6MHz -HSync +VSync
h: width 1152 start 1216 end 1336 total 1520 skew 0 clock 53.7KHz
v: height 864 start 865 end 868 total 895 clock 60.0Hz
1024x768 (0x6a) 65.0MHz -HSync -VSync
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
v: height 768 start 771 end 777 total 806 clock 60.0Hz
800x600 (0x70) 40.0MHz +HSync +VSync
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
v: height 600 start 601 end 605 total 628 clock 60.3Hz
640x480 (0x77) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 490 end 492 total 525 clock 60.0Hz
640x480 (0x2f4) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 489 end 492 total 525 clock 59.9Hz
720x400 (0x79) 28.3MHz -HSync +VSync
h: width 720 start 738 end 846 total 900 skew 0 clock 31.5KHz
v: height 400 start 412 end 414 total 449 clock 70.1Hz
steambox@steambox-MS-7786:~$