I've got a HDMI output problem with a Dell Inspiron 1525. I'm running Ubuntu 12.10. In the past HDMI used to work fine but now: Unsupported signal, check device output.
I've tried different cables and different HDMI ports on the TV (Sony 32KDL720) but to no effect. It works fine if I boot into Windows but nothing in Ubuntu (I don't want to use Windows). So it seems that it is not a hardware problem. Any help would be appreciated.