Possible problems in hooking to a tv
I have a computer that I built long time ago. It has and S-video output and the monitor output. Running Ubuntu 10.04. I connected the S-Video cable to the tv and the tv displayed the boot up screen clearly and on to the blinking cursor just prior to the Ubuntu coming up with the display screen with the logon. Then it just went fizzling. Looking in the hardware driver's I let it scan and it said it needed no proprietary drivers. When looking at the Monitor program, on the monitor now hooked up, it showed and unknown monitor. The availability of resolution choices dropped to 4 low end ones, IIRC the tops was 640 X 480 and I confirmed that it was on 60 Hertz setting. Playing with the resolutions changed the scraggly display on the tv, but none came close to any recognizable image.
When I unplugged the s-video cable the Monitor program displayed the full range of resolutions that the monitor was capable with the top being 1024 X 768.
Can anyone suggest an area of investigation that I might try, even to switching OS. I am stuck and have no further ideas. Thanks for any replies.