Help the second monitor doesn't work !
I can see some text from the booting process but it doesn't work or being detected.
-> When i boot the live iso the second monitor works fine but on my installed system it doesn't work.
I have an Nvidia that the main monitor is connected and
the Second Monitor is connected in the intergrated R7 gpu .
All the other linux distros has no problems detecting but on this distro it has problems.

Since it works in Live mode, it isn't a driver or kernel issue, so logs will be needed how you installed (selected to not use the non-free nvidia drivers? selected minimal install?). See https://kaosx.us/docs to get the output of SysInfo as a start.

    demm I have selected a normal install . Anyway i'm getting a dvi to vga cable this week so i can use only the nvidia gpu card and i will disable completely the intergrated gpu.

      demm The problem happens after i update my machine , when i reboot the second Monitor no longer works !
      ANY SOLUTIONS PLEASE ???

        As in my first reply, logs are needed, follow the link provided in that post to start.

          demm Ok i fixed the problem , i have removed amdgpu because it has a problem with xorg it requires newer version or something.
          I've installed xf86-video-ati i stopped sddm and xorg and i have executed X -configure then i copied the device section of the radeon (it has the PCI address) and adapted to the new xorg.conf file and now everything works fine.

          But i've noticed something stranger i have downloaded again the iso and after the update i had no Xorg only terminal what i did was to reinstall nvidia and execute nvidia-xconfig.

          Anyway the problem has been solved and now the second monitor works as it should.