I bought a Roku 4 Ultra recently because my Roku 3 seemed a bit slow in combination with YouTube TV, which I recently subscribed to after dropping my expensive "regular" TV package with Google Fiber.
I was getting frequent black screens, even in the menu, until I switched the Display setting on my Roku to 1080p from the default Auto. However, watching Netflix last night I got the black screen flash 2 or 3 times within a 2 hour period.
I'm running a Roku 4 Ultra through my Onkyo TX-NR545 receiver, and then to my Panasonic TC-P65ST50 plasma TV, using HDMI 1.4 cables for both segments.
The black flashes aren't very frequent, but then again my venerable Roku 3 never had this problem. Should I return it?
@AntonioCole Thanks for the note. If you are trying to use 4K display types or view 4K content or video, this requires the use of HDMI 2.0 capable ports that support HDCP 2.2, and certified HDCP 2.2 compliant HDMI cables. You'll also need to adjust the correct corresponding configuration on both your TV and your A/V receiver's settings for this video/display type. It's likely that wither your cables, or the display type configuration on either TV/A/V receiver may not be set up correctly for the functionality you are trying to use.
See more about HDCP 2.2 requirements here: https://support.roku.com/article/230317588-why-is-hdcp-2-2-important-to-playing-4k-ultra-hd-or-hdr-c...
You'll also want to check and see that you've disabled 'Auto-adjust display refresh rate' in Settings>System>Advanced system settings>Advanced display settings to help avoid black flashing behavior in some instances. https://support.roku.com/article/115012823268-how-do-i-change-the-display-refresh-rate-to-match-the-...
Keep us posted from there.
Thanks,
Tanner