When you did the swap to the new AppleTV, did you unplug anything from the receiver or was it simply unplug AppleTV 2 and then plug in newest AppleTV (with no cable changes on the receiver)? If any cables were fully disconnected, re-check your connections. It's easy to plug an HDMI cable into a neighboring jack on an Onkyo and not notice.
YES I HAVE DONE IT BOTH WAYS MULTIPLE TIMES. I DON'T THINK THIS IS THE ISSUE
I know Onkyo has menu settings to choose the input type: be sure the jack to which AppleTV is connected is set to HDMI instead of optical, analog, etc.
YES IT CURRENTLY USES HDMI WITH THE OLD ATV SO I KNOW THAT THE SETTINGS ARE CORRECT. AND I DOUBLE CHECKED
Have you tried unplugging the Onkyo, waiting a minute or two and then plugging it back in? Or did you basically "hot swap" with Onkyo turned on? A full reboot might be a solution.
YES I HAVE TRIED IT BOTH WAYS, HOT AND REBOOTED
I presume the projector does not have an HDMI OUT (which could go to receiver): AppleTV HDMI to Projector, Projector HDMI to Receiver? The preferred way would be AppleTV HDMI to Receiver, Receiver HDMI to Projector... but if Projector has an HDMI out, it might be able to send the audio to the receiver much like an ARC jack to a soundbar.
NO HDMI OUT ON PROJECTOR
If you rule all this out, you probably do need a new receiver. There's been a LOT of advancement since you purchased that one (it came out in 2008). Maybe move it to
another room and continue to enjoy it as a music-only hub? A couple of speakers and it will deliver great sound to another room. If you have a retired iPod, iPhone or iPad, sync your music collection to that device, hook it in and you have a fully independent music collection available in that other room.
The splitter options have been hit or miss for me- generally causing more trouble than they are worth. Yes, they can split out audio but then you may find that causes trouble for CEC functionality. I've tried several mostly to split out some analog audio for Zone 2 options on receivers, but I generally find I don't want them in the chain for other reasons.
YAH I GET THIS. I AM STILL GOING OT TRY ONE LAST TRICK WITH SPLITTER AND OPTICAL AUDIO, CREATING A WORKAROUND ON THE HDMI TO RECEIVER COMPLETELY. I AM STARTING TO THINK IT MUST BE THAT THE RECEIVER CAN'T HANDLE ANYTHING NEWER THAN HDMI 1.3.
For about HALF the price of a new iPhone, you can get a
spectacular 2020 receiver with all of the "latest & greatest" standards (some beyond the new AppleTV) and tech inside... that you can then use for the next 5-8 years or so before it gets too far behind the times. Maybe it's time?
HAHA YES I AM SURE IT IS. THANKS AGAIN!