After receiving my new LG 3D TV (32LW5700) I try to connect it to my ‘old’ notebook (Inspiron 6400 with an ATI radeon X1400) using a VGA cable getting only 1280×800). This also may be applied to 42LW5700, 47LW5700, 47LW9500 and 55LW9500 models.

After trying to get a modeline using cvt:

felipe@funstation $ cvt 1920 1080 60
# 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

Then add the modeline to Xorg with xrandr:

felipe@funstation $ xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

And activate it:

felipe@funstation $ xrandr --addmode VGA-0 1920x1080_60.00
felipe@funstation $ xrandr --output VGA-0 --mode 1920x1080_60.00 --below LVDS --right-of LVDS

And only I got an Invalid Format on my TV.

Then searching on the Owner’s Manual included in the cdrom (English version and Spanish version) distributed with the TV (the printed manual sucks!) I figure out that the vertical frequency was 59.934. I try with this new settings and I still got the same message.

Then I found GTF and using this program I finally found the right configuration:

felipe@funstation $ gtf 1920 1080 59.934 -x

# 1920x1080 @ 59.93 Hz (GTF) hsync: 67.01 kHz; pclk: 172.61 MHz
Modeline "1920x1080_59.93" 172.61 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync

felipe@funstation $ xrandr --newmode "1920x1080_59.93" 172.61 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync
felipe@funstation $ xrandr --addmode VGA-0 1920x1080_59.93
felipe@funstation $ xrandr xrandr --output VGA-0 --mode 1920x1080_59.93 --below LVDS --right-of LVDS

After this I was able to get 1920×1080 on the TV.

If you want to make it persistent try adding the commands on your ~/.xprofile

Now the next problem is to enable the 3D feature when using a VGA cable.