I'm trying to bring an unknown monitor up to full resolution.
It's a Visio E241-A1 (TV set), claiming 1920x1080.
I’m running Linux Mint 18.3 Sylvia, with Mate.
The computer (a new desktop) also drives an HDMI cable to a projector, but that’s turned off right now.

I used --newmode with xrandr and it seemed to accept that,
but then the --addmode said it didn’t know the new mode:

    xrandr: cannot find mode 1920x1080_60.00

Details below.
So, is there a way to make this work?

The Details:

xrandr: cannot find mode 1920x1080_60.00

Here's the advice I've been working for:

https://unix.stackexchange.com/questions/227876/how-to-set-custom-resolution-using-xrandr-when-the-resolution-is-not-available-i

Original source: https://gist.github.com/debloper/2793261

vodhner@MusicTeam ~ $ xrandr -q
Screen 0: minimum 8 x 8, current 1024 x 768, maximum 32767 x 32767
DP1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00* 
   800x600       60.32    56.25  
   848x480       60.00  
   640x480       59.94  
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis

vodhner@MusicTeam ~ $ gtf 1020 1080 60

  # 1024x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 92.30 MHz
  Modeline "1024x1080_60.00"  92.30  1024 1088 1200 1376  1080 1081 1084 1118  -HSync +Vsync

vodhner@MusicTeam ~ $ xrandr --newmode "1024x1080_60.00"  92.30  1024 1088 1200 1376  1080 1081 1084 1118  -HSync +Vsync

vodhner@MusicTeam ~ $ xrandr --addmode DP1 "1920x1080_60.00"
xrandr: cannot find mode "1920x1080_60.00"

vodhner@MusicTeam ~ $ xrandr --output DP1 --mode "1920x1080_60.00"
xrandr: cannot find mode 1920x1080_60.00
vodhner@MusicTeam ~ $ 

Thanks,

Victor
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