Black screen or sometimes white, no sound

So just bought a SNES had it shipped to my house, didn't come with a cord that goes to the tv so I bought a RCA one off of Amazon.

When I turn SNES with a game cartridge in, super Mario, I here the first second of sound and the screen stays black,. Sometimes after playing with cartridge for awhile I can get it to go from black to a white screen.

Is it perhaps my tv that doesn't support the device ? I have tried with 3 seperate tv. One of which said unsupported.

I've tried blowing cartridge out, using different ones and inserting and removing it about 20 times to try and knock dust free. But now I'm at a loss.

Any help would be greatly appreciated