I just upgraded to a Yamaha YAS-207 soundbar. All my devices (Xbox, Blu-ray, etc.) look and sound good through it. All except my trusty Roku 3 (4200x). Although the audio is good, the video flickers, jumping the display around for a millisecond, at least once or twice a second. I've swapped HDMI cables, tried forcing the Roku to 720p or 1080p, but nothing works. It still flickers.
Bypassing the Yamaha eliminates the Roku flickering, so obviously it's something between the Roku and the Yamaha, since every other device works fine.
There are 4 devices (Roku, Xbox, Blu-ray, cable box) plugged into an HDMI switcher, which then plugs into the Yamaha, and then to a projector.
All the devices work fine in this configuration except the Roku, as described above.
If I plug the Roku directly into the Yamaha, bypassing the switcher, the flicker remains. If I plug the Roku directly into the projector, the problem disappears. Switching cables does not help.
Besides the Yamaha I realized there is one other new aspect of the system: I relocated the projector so I needed an HDMI cable run that is longer than before. From the Yamaha to the projector is a 25ft HDMI cable. Add about 5ft from the switcher to the Yamaha and another foot to the Roku.... Now I am wondering if the Roku can't push the signal that far, but the other devices can.
Roku players do seem to be more sensitive to longer HDMI cable runs. Even though you aren't running 4K, a certified 18 Gbps cable might make it work.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.
I've replaced all the cables involved with certified 18Gbps HDMI cables, and tried a variety of tests with the Roku 3, Yamaha Soundbar, and Optoma 1080GTDarbee projector. As noted above, the setup works fine for every other device I throw at it (Blu-ray, cable box, Xbox), but here is what I get with the Roku....
VIDEO WORKS FINE:
Roku -> 25ft -> Projector
Roku -> 3ft -> HDMI signal booster -> 25ft -> Projector
Roku -> 3ft -> Soundbar -> 3ft -> HDMI signal booster -> 25ft -> Projector
Roku -> 3ft -> HDMI/optical audio splitter* -> 3ft -> HDMI signal booster -> 25ft -> Projector
Roku -> 3ft -> HDMI signal booster -> 3ft -> Soundbar -> 10ft -> Projector
Roku -> 3ft -> HDMI signal booster -> 3ft -> HDMI/optical audio splitter* -> 10ft -> Projector
* this powered box passes through the HDMI signal while splitting the audio to an optical cable for the soundbar
In short, whenever the Roku 3 is plugged into one of these particular HDMI devices that extracts audio (the soundbar or optical audio splitter), the video flickers. This means I can't connect the Roku 3 to an audio output device (and no, the speakers built into the projector are not suitable).
I also took my Roku to another setup and plugged it into an expensive Yamaha audio/video receiver (part of an installed surround-sound system) with a different projector and a total HDMI cable run of about 30ft, and it worked fine. **grumble**
Any further thoughts? I am computer savvy but I don't fully understand the HDMI handshaking and HDCP stuff, so I'm wondering if there is an issue there somehow. Maybe not. I have no idea, but I've read plenty of other discussions about it.