I had my myth setup working all fine with a 120 gig hard drive. Recently I was given a 320 gig hard drive so I decided to use that instead of the 120. I would use LVM for the new drive but I want to use the old 120 in my computer for some extra storage. I replaced the hard drive and then ran through the Knoppmyth setup just as I had done with the initial install. When everything was finished I tried to hit watch TV and all I got was the black screen and then dropping back to the main window. I thought that I had just forgot what my channel frequency was and put in the wrong one. So I ran the mythtvsetup again and change the value. Started the frontend up again and tried watching TV and still got the black screen. I put the old hard drive in and booted up to double check my frequency table. It was the same as the first one I had tried on the new hard drive. I hit watch TV on the old hard drive and it displayed the videos no problem. I couldnt figure out what was going on so I tried a guided setup I had seen earlier that uses Ubuntu Edgy. I ran through the guide and installed everything. One step was to test your setting and get video via Mplayer. Ran that step and got TV coming through via Mplayer. Finished the guide and installed Myth. When got into the main menu I hit watch TV and again am getting the black screen. I don't get what could be going on.

See the troubleshooting pages on the wki. http://www.knoppmythwiki.org/index.php?page=BlackScreenWatchingTV

My first guess is that you either set up the capture card wrong (if you'd said more about your hardware we could have told you the exact setting to use), or forgot (over did) the input connections.