[Stop the Crashes]

My cable system has a few 4K channels at 60 fps. When I tune my Bolt to any of them, the TiVo recognizes the 2160p signal, but sends a dark and undersaturated picture to my Samsung QLED 4K TV. The sharper detail of the 4K picture is evident compared to the 1080p picture, but it is unwatchable because of the darkness and color issues. While in that mode, the banners on the info and guide screens are almost black.

Furthermore, when I fast forward or rewind, there is a second or two of black screen, followed by a much brighter and well saturated version of the picture while fast forwarding. If I press pause during ff or rewind, the still picture is bright and well saturated. The info and guide banners while in rewind / pause mode are the proper shade of blue. Clearly, the correct information is there somewhere in the signal. When I go back into "play" mode, the dark, undersaturated picture reappears. The momentary black screens during mode shift would be consistent with a resolution change, but while fast forwarding or rewinding, the info screen still says 2160p and the picture is still sharper than 1080p. Still, it seems that some sort of HDMI renegotiation is occurring.

I have tried every resolution setting offered on the Bolt, but the problem persists. I've also tried various HDMI cables, with no effect. I've tried every picture setting available on the TV with no improvement. I've also tried switching to PCM audio, as mentioned in a couple of other threads, which you wouldn't think would have any effect, and it didn't.

As an old computer programmer and IT guy, I'd like to believe I'm a pretty good diagnostician, but I've run out of things to try. I wonder if it might have anything to do with bitrate. Perhaps a 4K requires a newer cable card?

I bought the Bolt because of its 4K QAM capability. It's very disappointing that it seems unable to deliver that key feature, and that other threads on this subject have apparently been largely ignored by TiVo. I post this in hopes of getting some attention and effort from TiVo toward fixing this.

 

[pl1]

Furthermore, when I fast forward or rewind, there is a second or two of black screen, followed by a much brighter and well saturated version of the picture while fast forwarding. If I press pause during ff or rewind, the still picture is bright and well saturated. The info and guide banners while in rewind / pause mode are the proper shade of blue. Clearly, the correct information is there somewhere in the signal. When I go back into "play" mode, the dark, undersaturated picture reappears. The momentary black screens during mode shift would be consistent with a resolution change, but while fast forwarding or rewinding, the info screen still says 2160p and the picture is still sharper than 1080p. Still, it seems that some sort of HDMI renegotiation is occurring.

For the black screen during trickplay, I think it might be the Samsung TV. In this thread "Verizon FiOS: First 4K broadcast tonight 5/11", we were discussing this issue, and three of us have a Bolt & Fios 4K. Two of us have Samsung TV's with this symptom. Poster @aaronwt who has other TV brands does NOT have the problem. For the other parts of your symptoms I'm no help.

 

[Stop the Crashes]

For the black screen during trickplay, I think it might be the Samsung TV.

Thanks. Maybe I'll take my Bolt to a friend's place and try it with her Sony.

 

[aaronwt]

My cable system has a few 4K channels at 60 fps. When I tune my Bolt to any of them, the TiVo recognizes the 2160p signal, but sends a dark and undersaturated picture to my Samsung QLED 4K TV. The sharper detail of the 4K picture is evident compared to the 1080p picture, but it is unwatchable because of the darkness and color issues. While in that mode, the banners on the info and guide screens are almost black.

Furthermore, when I fast forward or rewind, there is a second or two of black screen, followed by a much brighter and well saturated version of the picture while fast forwarding. If I press pause during ff or rewind, the still picture is bright and well saturated. The info and guide banners while in rewind / pause mode are the proper shade of blue. Clearly, the correct information is there somewhere in the signal. When I go back into "play" mode, the dark, undersaturated picture reappears. The momentary black screens during mode shift would be consistent with a resolution change, but while fast forwarding or rewinding, the info screen still says 2160p and the picture is still sharper than 1080p. Still, it seems that some sort of HDMI renegotiation is occurring.

I have tried every resolution setting offered on the Bolt, but the problem persists. I've also tried various HDMI cables, with no effect. I've tried every picture setting available on the TV with no improvement. I've also tried switching to PCM audio, as mentioned in a couple of other threads, which you wouldn't think would have any effect, and it didn't.

As an old computer programmer and IT guy, I'd like to believe I'm a pretty good diagnostician, but I've run out of things to try. I wonder if it might have anything to do with bitrate. Perhaps a 4K requires a newer cable card?

I bought the Bolt because of its 4K QAM capability. It's very disappointing that it seems unable to deliver that key feature, and that other threads on this subject have apparently been largely ignored by TiVo. I post this in hopes of getting some attention and effort from TiVo toward fixing this.

I don't have these issues from a Bolt on FiOS. With a SOny, TCL, and Hisense UHD TVs. Whether the 2160P signal has SDR, HLG HDR, or HDR10 HDR they have all been fine when watching 2160P60 QAM content on the Bolt. This has been with the Bolt connected directly to the TV and using the ARC for audio.

 

[Stop the Crashes]

Update: I have now tested my Bolt with a Sony 4K TV. It produced the same symptoms as with the Samsung, so I have to conclude it is not a Samsung issue. I also tried replacing the cable card, with no effect. So the problem must be either with TiVo or with RCN, but my strong hunch is it's a TiVo issue. We know that recordings from the RCN 4K channel have the proper information somewhere in them, as evidenced by the correct brightness and saturation during FF and rewind. The black screen when switching playback modes would seem to indicate a renegotiation going on between the Bolt and the TV, but we now know that it's not just Samsung TVs. Now I think I've reached the end of things I can test. I sure would appreciate TiVo looking at this, since the ability to watch and record 4K cable programming is why I paid for it, and it delivers neither.