apple tv says unsupported mode when plugged into tv

My Apple TV 4th Gen says "unsupported mode". It worked fine for ~10 months then started showing this error. If I plug in my 2nd generation Apple TV using the same HDMI it works fine so it's not the HDMI nor the TV. I don't have an USB-C cable so I can't restore my Apple TV 4th gen via iTunes.

Any ideas?

Hi AppleTVUnsupported. First, it is your TV that says "unsupported mode", not Apple TV. Second, your Apple TV has maximum resolution of 720p, not 1080p, which may be why it works. Do you know what video modes your TV can accept? Have you tried using the remote to cycle the video modes, like this:

On the remote, hold Menu and Volume down (Menu and Up for older ATV) for 5 seconds. ATV will then switch to a new format (resolution) every 20 seconds. That's only 3 times a minute, so be patient. When you see a prompt, use the remote to accept the result.

If it's working on another tv then the issue lies with the insignia

have you tried to lower the resolution using the other tv and then connecting it to the first one ?

Suggest you follow the blank screen section of this guide to correct your problem:

Get help with audio, video, or power on Apple TV - Apple Support

Try setting the resolution to automatic.

I've noticed that ATV starts in 720, then switches to the selected resolution. That's why you see the initial Home screen. When ATV switches to the selected resolution, your TV reports unsupported mode. My guess is that you're sending 60 Hz video to a 50 Hz TV, or the opposite. Your other set probably supports both update rates, so it works.

Since you cannot see the screen, try the trick in the referenced help page, using the remote to cycle through the resolutions.

Be sure the cable is good and connected straight and tight.

Hello danielsuedbeck,

I see you marked this as solved. I hope it is. Just for my info, was it the cable, or what resolution setting turned out to be required?

Thanks, Di