New LCD TV. Help!

[mario_bro2065]

So I recently got a small 4:3 LCD flatscreen TV. I got it because my grandma passed away and my uncle who lived with her said I could have it because they've got no use for it. They said I could use it to replace the CRT I used for my retro consoles. I also got a Sega CD and a copy of Ecco the Dolphin CD.

Now here's the problem. I tested out the Sega CD on the CRT and I know it's working so it's not the console. The problem is my Sega CD is outputted through a Signal Box leading to Coaxial (Don't kill me I know I should have RCA  ). I have to tune in to either channel 3 or 4. But when I change the channels. There is none. Prolly because she used Satellite or whatever. I'm not an expert on TV stuff. The closest I can get to either Channel 3 or 4 is Channel 4-1. But nothing appears when I change it to that. This means most of my other Coaxial consoles (Atari 2600, N64, etc.) won't work with this TV. Anyways I can make the TV search for a Channel 3 or 4? Please help!