Apple TV 4k WakeUp Issues

I have an Apple TV 4K (2 actually). One is connected to my 55" Samsung 4k tv and the other to my 40" Samsung 4k tv. I had this problem also and calling Apple got me nowhere. Exasperated after a month of trying to figure it out, I remembered that I changed a setting in my 'Video and Audio" settings. There is a setting called 'Chroma' which is set to 4:2:0. I changed this to 4:4:4 because the description said that the 4:4:4 setting "improves clarity, but requires high-speed cables." I had high-speed cables and who doesn't want a better picture? When set to 4:4:4, the signal sent to my Samsung is enough to wake the Samsung, but with no picture. I've tried different cables to no avail. My Apple TV only behaves as expected when Chroma is set to 4:2:0. I know this because I clicked on 'Reset Video Settings' and the ATV reverted back to 4:2:0 and everything works again. I can wake it from sleep even when I'm already watching my Cable box and it comes on immediately. I can even restart it with the remote again.

It’s not a Samsung issue or cable issue - one of my atv4k’s works fine every time, while the other unit experiences this issue (same tv, and problem manifests itself on whatever tv the faulty device is on).

I called Apple support yesterday and they’re sending me a new unit.

I believe I've found a fix. I have a Samsung 6-series UHD TV (KU 63XX series) and was having tons of wake from sleep issues. In scouring the internet, I found that my Samsung TV only supports HDMI UHD Color mode (Picture -> Expert Settings) for HDMI 1 input. I swapped some cables around and voila the issue disappeared.

I'm not sure why, but I've heard this type of connection is what the AppleTV is expecting?!

don't know what it worked for me. Best of luck all!

Thank you. I was pulling my hair out with my Samsung MU Series tv. I just disabled HDR and it worked fine. Tried all 3 hdmi ports and it won’t wake up with hdr enabled but works fine with it off.

I did two things and the Apple TV 4K hasn't failed to start since. Consequently I don't know which worked or if i've just been lucky so far. First I did an Apple TV 4K Reset and secondly I went to the store and purchased a GE Certified HDMI Cable. I would ordinarily think the HDMI cables I had were fine, but after reading so many threads and posts with HDR issues where changing cables appeared to have fixed things I think it was worth trying.

I continue to intermittently have my atv4k wakeup issue where no signal is detected by my LG 65 OLED E6P. This happens about 50% of the time. When it happens I have to power down and back up the Apple TV 4K. You can do this by two different methods. First you can simply pull the power cord and then plug it back in, or second you can hold the atv4k Remote Menu button and Home button simultaneously for about 6 seconds. This second method will cause the atv4k to power down and power back up as if you had unplugged the power cord and then plugged it back in. This is easier than getting up and and physically removing the power. After either of these methods the signal is detected 100% of the time.

I have taken every step I know to take to ensure it is not the HDMI cable or the LG 65 OLED E6P TV. I went out and bought the latest and greatest premium certified 4K UHD HDR HDMI cables. I checked to ensure that the TV was updated to the very latest Software/Firmware. I ensured the TV was set to allow the atv4k to power the TV on/off. I checked to see that the when a signal was detected and working that indeed 4K HDR was being achieved. I ran the Cable Check from the Setting Menu on the Apple TV 4K. I also did a complete Reset of the Apple TV 4K.

It is hard to fully understand why the Apple TV 4K always sends a good signal if the AC Power is freshly applied, but only works about 50% of the time if AC is connected but the Apple TV 4K is waking up after being asleep. I guess what actually is occurring is that this fault occurs intermittently only if the Apple TV 4K has had a chance to sleep for a time.

I am still within my Return Period and did purchase my Apple TV 4K directly from my nearest Apple Store, but I did make an appointment with the Genius Bar for next week to have a technician do some diagnostics on the device. Until then I don't know of anything else to try.

I buckled and exchanged my Apple TV 4K yesterday at the Apple Store. The Store representative said that Apple will be happy to send me an email letting me know what they discover as they diagnose this particular issue. The new unit connected via the same HDMI cable to the sale LG 65" OLED TV is working flawlessly. Every time I go to use the Apple TV 4K the signal is detected appropriately on the same HDMI2 Port and thus I am now paying full attention to the actual
TV Shows / Movies than I am to any problem resolution or mitigation.

I tried almost everything suggested here in the forum and finally i found the solution which works for me like a charm. I changed the HDMI Port of my 4K Apple TV from the first one to the second of the four I have on my 65" Samsung KS9080. Switching it off finally works now like before when I bought that thing. I still hope Apple delivers an update cause this was truly annoying while it lasted.

Then yes, the tv4 32gb running tvOS11.

And yes, problem follows device to any tv/cable plugged into it, while another atv4k work fine on same tv with same cable. Problem follows faulty device and Apple has agreed to send me a replacement.

As a follow up to my previous post, I exchanged for a new Apple tv 4K, but that didn’t help. I noticed that this issue only occurs when I have Dolby Vision selected on the Apple TV. When I switch it to HDR, it works fine.

I’m just doing to leave it on HDR AND wait for 11.2.

So I just did a restore of my Apple TV 4K, and now it works again like its supposed to. It must be a software issue then...

I have an LG 65" OLED TV and at least 50% of the time when I turn the Apple TV 4K on and the LG TV on the TV screen is blank and an LG popup says no device or source was found. I click on a button to list all devices and there are no devices showing on HDMI 2 where the Apple TV 4K is connected. When I unplug the Apple TV 4K and then plug it back in the connection shows the Apple TV 4K and everything is displayed appropriately. The fact that things work fine about half the time, tells me it is software related. In my case the Apple TV 4K is directly connected to the LG 65" OLED TV's HDMI 2 port.

I have this aswell. It worked flawless for the first week or something. Now it wont wakeup. I dont lose the signal while watching anything. But I can't wake it up. My tv (lg oled55b7v) cant see anything, and the first week I would turn on the Apple TV, and the tv would start. I have a direct HDMI from Apple TV to TV. I cant see anything now.When I turn it on, I just get a black screen, no preview or anything. If I pull the plug, it comes up and works fine. As it has worked i suspect its a software issue. I have just reset my Apple TV, I will let you know if this helps. Hope Apple sees this...

I'm running a Samsung 65" 4K tv as well, and when it's on, it looks great when it works, but it seems like once it sleeps, it won't come back up. At one point it even dropped the signal to the TV while playing something from Netflix. Like you, I had to unplug and replug the unit in order to get the tv to recognize the Apple TV 4K. I've been running a 4th Gen ATV for months and in that time never had a single glitch like this.

Hi, maybe it has to do with another issue. Although I told my Apple TV 4K to fall asleep after an hour, it won‘t do this - for hours and hours. And as I can‘t go back to my Apple TV on my Samsung SUHD (black screen), I have to pull the plug and start again. But this doesn‘t happen when I finish my Apple TV session telling it to fall asleep at once. Then the LED is definitely out (and of course my TV too). The problem: When I turn on my TV afterwards, it switches on the Apple TV!!! The only chance: Before telling my Apple TV to fall asleep, I‘ve got to change my TV to Live TV and after this, I can turn off my Apple TV - okay, my TV then shuts automatically down, but this is no problem. After turning it on again, Live TV is playing and my Apple TV is still sleeping.

Oh Apple, life could be so easy, if you would make a good job....

My question: Does your Apple TV 4K fall asleep as you told it or do you have the same issue as I have?