Re: [Trisquel-users] Problem with the output to the external Monitor

[lcerf]

/etc/modprobe.d/disable-radeon.conf blacklists the radeon driver. Comment its  
only line by making it start with "#":
$ sudo sed -i 's/^/#/' /etc/modprobe.d/disable-radeon.conf
Then update the initramfs:
$ sudo update-initramfs -u

A reboot later, the problem might be solved.