Unable to change screen resolution on Raspberry Pi 3 Model B

[itzdk]

When I first boot up its running at 656x416 on my 4K monitor. In the display settings there weren't any other options. I found bits of info on various blog posts and tried to use:

cvt 1920 1080 60

which returned

Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

After that I used xrandr to create a new mode

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

Which returned the error

xrandr: Failed to get size of gamma for output default

But I saw some people mention that this error was harmless so I continued. Using xrandr at this point I could see my new mode in the list. I added the mode

xrandr --addmode default "1920x1080_60.00"

which gave that same error again. But this time in the screen settings I could see the new resolution option. But when clicking and applying this resolution nothing happened. I then tried to set the size with xrandr

xrandr -s "1920x1080_60.00"

and even with sudo I kept getting the same error

Failed to change the screen configuration!

I tried to restart after doing this, but after restarting I couldnt see my new mode in xrandr or in the system settings. Does anyone know how to fix this?

[melsi]

I also have this issue, did you find a solution?

Thanks

David

[RAZERZDAHACKER]

When I first boot up its running at 656x416 on my 4K monitor. In the display settings there weren't any other options. I found bits of info on various blog posts and tried to use:

cvt 1920 1080 60

which returned

Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

After that I used xrandr to create a new mode

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

Which returned the error

xrandr: Failed to get size of gamma for output default

But I saw some people mention that this error was harmless so I continued. Using xrandr at this point I could see my new mode in the list. I added the mode

xrandr --addmode default "1920x1080_60.00"

which gave that same error again. But this time in the screen settings I could see the new resolution option. But when clicking and applying this resolution nothing happened. I then tried to set the size with xrandr

xrandr -s "1920x1080_60.00"

and even with sudo I kept getting the same error

Failed to change the screen configuration!

I tried to restart after doing this, but after restarting I couldnt see my new mode in xrandr or in the system settings. Does anyone know how to fix this?

Try sudo nano /boot/config.txt
You should be able to change screen resolution and more from there.