Problem connecting old desktop with Ubuntu 20.04 to LG tv
I installed ubuntu 20.04 to an old Dell Optiflex 755 desktop connected via VGA cable to a LG 32LD420 tv. With the default resolution 1024x768, the tv display was ok. I tried to configure it to 1920x1080 (60kHz) which is the recommended resolution for this tv using cvt and xrandr --newmode and --addmode. When executing the commands from the terminal the screen went black showing a No Signal message. I tried making the change permanent by creating a /etc/profile.d/external_monitor_resol.sh and the display appeared on the tv but distorted, actually it looks compressed horizontally with a black band on the left-hand side, while vertically looks ok (see screenshot). Some extra info:
- When I connect a computer monitor to the pc the display works fine at 1920x1080.
- The tv is not recognized (Settings>Display: Unknown Display).
- The same pc, before installing ubuntu was running Win7 and had no display problem connected to the same LG tv.
Could it be an issue with the parameters of the xrandr new modeline? Would an upgrade of the tv s/w solve the problem? Can you please help?
