My Amazon TV Firestick won’t turn on an Element TV

I brought my Amazon Firestick to my boyfriend’s house and plugged it into his tv. It won’t turn on at all. I’ve tried both HDMI ports, I’ve tried unplugging it and letting it “boot up”, I’ve tried turning off the tv, I’ve tried changing the batteries in the remote, I’ve tried “resetting” it and nothing is helping. It’s still plugged into the external power source. The screen just says no signal and stays blue. Nothing is popping up. What am I supposed to do?