Humm...well, I take it that you are using the Amiga 500s composite video output and hooking that into a video input on your TV. If that is the case there may be something wrong with the composite output on the Amiga or the input on the TV. You should at least see something. The composite out will not show as much detail as an RGB monitor and the colors may be wrong. You would need a composite to video converter.
I had my A500 setup like this (without a converter) a few years ago and it worked ok.
Let us know if you have a different setup. And make sure you are using a video cable.
