FWIW, I don't think it's a problem with the Roku itself - at least not in my case. I've been using my Roku Premiere for a year and half and never had this problem. But suddenly it starts doing this and so does my new Roku 4K Express +. It seems like something has changed - maybe due to an update?
Regardless of it being a hardware or software problem, they haven't stepped up to the plate to try to resolve it. A bunch of people have posted similar problems in this thread with several different units; we can't all be wrong. If a system update is required to resolve the problem every time we turn it on, this is pointing to a pretty definitive problem with their software. Roku needs to create the solution, but so far haven't addressed this issue for months now. They have now created frustrated customers and they don't seem to care period. I have no problem telling people that Roku is unsatisfactory as a result and spend your hard earned money elsewhere at this point.
Can you please provide us the following information:
-Roku device model, serial number, device ID, and software OS/version (these can all be found in Settings > System > About)
-does this issue occur on a specific channel? if so, what channel and what version/build is the channel (this can be found be selecting the channel on the Home screen and pressing the * button)
-tracker ID when this issue occurs (when you see this issue occur, press the Home button 5 times, followed by the Back button 5 times)
-steps to reproduce the issue you are seeing
Once we have this information we will be able to pass it along to the appropriate Roku team for further investigation.
The problem occurs on all channels on both Rokus. The menus, Roku Home Page, captions, etc. all appear just fine but the actual video on a channel [Netflix, Hulu, Amazon Prime, YouTube, YouTube TV, etc.] is black.
It seems to occur when the Roku has been unplugged or left idle for some time [overnight, for example]. I can consistently solve the problem by going to Roku Settings>Display Type and selecting Auto Detect, even though it is already set for Auto Detect, then confirming the setting. After that video appears just fine on all channels. But it's quite a hassle to have to do this every time I sit down to watch TV.
On the TV connected to the Premiere, I get the error screen "HDCP Error Detected" when I first try to play a video after being idle. After I do the correction described above, no errors.
How are you powering the Roku device? Is the device plugged into the TV USB port or is it plugged into a wall outlet? In addition, when you are not using the Roku device are you are you making sure to return to the Home screen, or are you just turning the TV off?
With more detail information we will be able to assist you further.