Created attachment 5388 Output of XFSETTINGSD_DEBUG=1 xfsettingsd --replace --no-daemon I am using a daily build of Xubuntu 14.04 x64 (XFCE 4.10) on a Lenovo Thinkpad x230. If I switch to using an external monitor and then switch back to using the built-in display, the brightness controls no longer work. The applet shows the brightness value changing, but the screen's brightness does not change. The only ways I have found to fix it is by logging out and back in, rebooting, or putting the system in standby and waking it back up. I have attached the output of: XFSETTINGSD_DEBUG=1 xfsettingsd --replace --no-daemon while reproducing the problem.
Since the display brightness is actually handled by the power manager, I'm moving the report.
More information is needed here. 1) Quit xfce4-power-manager with "xfce4-power-manager -q" and start it in no-daemon mode "xfce4-power-manager --no-daemon" to get a log. 2) Track the values in the kernel sysfs, like /sys/class/backlight/<your-machine's-backlight-name>/brightness /sys/class/backlight/<your-machine's-backlight-name>/actual_brightness /sys/class/backlight/<your-machine's-backlight-name>/max_brightness ...
No response, closing.