I have 2 monitors, one connected with a hdmi cable to my pc and one connected with a vga cable and a dvi-i to vga adapter, plugged in the dvi-i port of my gpu.
Under Windows 7, it works perfectly but under debian 9 (lxde), i dont get an output. xrandr gives me only my hdmi connection.
In Menu > Settings > Monitor Settings is only the hdmi monitor displayed.
My graphic card is amd radeon r9 270, drivers are installed.
I have tested this setup with other desktop environments either but with no success.
The second screen works during boot just when lxde starts, it looses the signal.
To buy an other hdmi cable is no solution because my gpu has only one hdmi port (and 1 dvi-i, 1 dvi-d and a display port). Also a dvi to hdmi cable didnt work (pc - dvi - hdmi - monitor)
My target is to extend my desktop.
I have downloaded my gpu driver here
and executed the file after download.
My package manager (synaptic) tells me that the drivers are installed (I have searched for radeon)
I haven't configured my display because debian doesn't discover it.
"and yes, I have asked Google..." yes, there are thousand guides out there how to setup dual monitors. Most of them did not faced my problem. Under linux, my 2nd monitor is not displayed at all.
K7AAY: It is not the hardware's fault because my monitors are working fine with win7. Its anything with linux...