Maybe your text console display has a resolution/timing yout LCD TV does not know (yet). You can test this by bootung Ubuntu and after graphics mode is ready, pres Ctl-Alt-F1 to switch to the first console (maybe first is occupied, then try Ctl-Alt-F2).
Then try to Auto-Sync your LCD-TV. Mine has a key for it, maybe your's, too. Otherwise search the TV's menus for an aut-Sync option.
A HDMI/DVI cable is likely to help (if it's a resolution problem), but I am not sure enough to propose buying one without previous testing. Can you borrow one frome one of your friends ?
EDIT:
Interestingly, my TV has a native resolution of 1280x768 and I had trouble setting my X server to exactly this resolution. In the beginning, I could only have either 1280x720 or 1024x768, both being stretched to fullscreen. And I still am unable to set this resolution on the console and the bootsplash.
The reason is that 1280x768 is a rather unusual resolution.
I am using AMD onBoard graphics, so my suggestion may or may not work on your PC. What I know is that the modesetting differs between AMD and NVidia. So you may need to do some more research for the details.
My suggestion is to try and set the console resolution to 1024x768 in /etc/default/grub and do an update-grub. With my AMD graphics, I can just specify GRUB_GFXMODE=1024x768. Maybe you need to determine the video mode number with your NVidia.
If you see a grub menu but no console when Linux starts booting, you should try to set GRUB_GFXPAYLOAD_LINUX=keep to make the Linux kernel keep the resolution from grub. The GRUB_GFXPAYLOAD_LINUX is from ArchLinux (I'm experimenting with) but should work on Ubuntu too. If it works, it will be stretched a bit too, but I think on console, this is not very bad. And better than nothing. ;-)