Why won't the TV recognize my N64?

Hi! I was feeling pretty nostalgic recently and got an N64. It worked for a few plays, but I've been trouble recently. The N64 turns on just fine, but the TV won't recognize it---it gives me a "no input" error.

I thought it might just be AV cables going bad (they were pretty old) so I replaced those, but no dice.

I did just get an expansion pack to play Majora's Mask, but it worked after that for about one play. Since then it hasn't.

I've tried different ports to make sure I have the AV cables in the proper place, and nothing appears to help. I've plugged it into TVs not connected to satellite, I've disconnected other gaming devices, I've tried everything I can think of. Does anyone have any suggestions?

i've tried it on multiple television sets, by the way, in different households.