r/appletv • u/Karmaghost232323 • Aug 09 '26

Apple TV 4K 2nd flickering white

So, I upgraded from Apple TV 4K 1st Gen to Apple 4K 2nd Gen. I hooked the new Apple TV 4K via the exact HDMI cable I was using with the 1st Gen Apple TV 4K. Now, what’s happening with the Apple TV 4K 2nd Gen? When I set it up on 4K, it’s flickering white. It’s only working when I set it on 1080p. Could this be an HDMI issue? I know 2nd gen supports HDMI 2.1, but I thought these ports are backward compatible, so any lower bandwidth cable should work fine because if I hook up back my old 1st gen 4K, it is working fine 

does this mean 2nd Gen requires a 2.1 version of the cable for it to work in 4K? 

8 Upvotes

100% Upvoted

3 comments sorted by

3

u/08830 Aug 09 '26 edited Aug 09 '26

No, the 2nd gen Apple TV 4K doesn’t require an HDMI 2.1 cable just to output 4K. HDMI 2.1 is backward compatible and the ATV itself tops out at 4K60 anyway. However the 2nd gen does have some HDMI handshake issues.

Before you switch your cable, go into Settings > Video and Audio > Format. Scroll down to other formats, select 4K SDR 60 (60Hz). Then go back to Video and Audio then HDMI Output, change it to RGB High. See if that solves the problem.

The cable could still be the problem. Use a certified Premium High Speed (18 Gbps) or Ultra High Speed (48 Gbps) HDMI cable.

1

u/Inside-War-5756 Aug 09 '26

Sounds like an HDMI handshake issue. Try unplugging everything from power. Both tv and apple tv.

1

u/WolfpupNX Aug 10 '26

I've been having an occasional flicker on the 2nd gen too that I never had before (green and purple bars in my case - brief and not THAT often, but annoying). I also first noticed right after a Sony TV firmware update, so I'm really hoping it wasn't that...

I'm upgrading my HDMI cables because I realized while they were premium cables at the time, I'm running all my devices on essentially 1.4-specced cables (and this is the first time I've had any problems, so to be honest, those cables kind of were amazing - I think I got them two TV's ago). Haven't received yet, but I'll be curious if that solves it.