LG TV No signal with Apple Tv

Well, I think I figured it out.

After I unplugged the Apple TV to get the home screen on the LG TV, I jumped into the settings on the Apple TV and checked the video output one more time to make sure that setting matched the setting on the LG TV.

I have the LG TV set to 4k HDR. The settings on the Apple TV were actually set to 4k SDR. I changed the setting to 4k HDR.

The true test would be turning on the Apple TV in the morning to see if the LG TV would go straight to the no signal screen. The reason is, over this last week, once I got the home screen up on the TV it would work all day but I would come in the morning and turn it on and it would say no signal until I unplugged it and plugged it back in.

I came in to the living room this morning, turned on the Apple TV and waited... It turned on the TV like it was supposed to and BOOM! The home screen came back up. I think that one setting was the only thing different and that fixed it.

I want to say thank you for vazandrew and ckuan for walking through this troubleshooting path with me. It really helped.

That doesn't make a lot of sense. I can get it to work just fine if I unplug the Apple TV and plug it back in. For example, right now, I am watching Mad MAX on that LG TV with the 4K HDR setting with no glitches or problems. I am not experiencing any issues once I get it to connect. If the cable or port was an issue, I would not be able to get it to work at all or I would be experiencing static and playback/refresh issues. This is just an initial signal connection issue.

All of this worked on the other TV just fine. I upgraded two cables when I installed the new TV (I am not using the 10 year old HDMI cables). I have also tried other HDMI Ports and the other HDMI cable on the TV with the same result.

Both the TV and the Apple TV have the most recent software upgrades as well.

I have done all of that. (See my edit on my reply). Look, the cables I upgraded to were $40.00 a piece. They were the most expensive cables that Best Buy had to offer and the package said SDR/HDR on them.

Okay, the saga continues. I came home from work and ran some more troubleshooting tests. It is definitely not the new LG TV. I grabbed a BlueRay DVD player out of my bedroom and plugged it into the same HDMI port as the Apple TV, with the same HDMI cable. The TV saw the player and the BlueRay movie played flawlessly. I plugged that DVD player into every single HDMI port on the TV and they all worked great.

I went out and purchased another (more expensive) cable. I plugged the Apple TV into the same HDMI Port as before (HDMI 1), turned the TV on and... nothing. I still get a no signal message. This cable says right on the box that its designed specifically for high speed 4k Ultra HD/HDR TVs. It says it can handle speeds up to 18 GBPS.