Fire tv cube freezes on startup at fire tv logo, then no response from remote or Alexa.the light on Cube stays blue. tried everything to sort this.if i add another tv to the setup instead of hisense tv, it works perfectly again.Any ideas as I hitting a brick wall here.thanks
By any chance are you using a soundbar? I had a similar problem with my TCL Roku TV. I have an Apple TV 4K and it would freeze and show a black screen. After hours of troubleshooting I found that the problem wasn't the TV or the Apple device, but rather the soundbar. It was a TCL Alto 9+.
I had the Apple TV 4K connected to the TV's HDMI 1 port, the soundbar connected to the TV's HDMI ARC port, and for whatever reason, the soundbar was causing the whole problem. TCL sent me four replacement soundbars because the first three were all defective.
I also tested those soundbars as PC monitors, also connected from PC > HDMI ARC port, and every time I'd switch to the PC my screen would go black, the PC would stop responding, and I'd have to restart the computer to get it working again.
The fourth replacement soundbar finally worked fine.
So if you have a soundbar connected to the TV via HDMI, the soundbar might be the problem. Otherwise, I'm not sure what's causing it.