AV cable Problems No Signal

Hi there!

So I have been having trouble with my Snes, I bought myself a RCA Cables to be able to hook them up to my TV/Monitor(I use an upscaler), and the same thing happened with both of the cables them.

I turn on the console, the works great and suddenly I get no signal message. and then nothing. It happened with both of the RCA Cables. I tried on various TVs and monitors. Sometimes I get sound but no image.

Is this a problem with the connector on the console? I cleaned the console but the solder points may be old and need to reflow them, I can add photos tomorrow.