External monitor not working in newer Kernels

[Thomas Waldecker]

Hi,

my external monitor (HDMI) stopped to work after the update from
kernel 3.7.8-202.fc18.i686

I'm using MATE and with the System > Preferences > Monitor Preferences
tool I'm trying to enable the second screen.

The second screen is just black in kernel 3.8.3 and 3.8.2.

Please let me know if you need some debugging info.

Kind regards,
Thomas Waldecker