Dolby Vision Glitches on Panasonic DP-UB820P-K (1 Viewer)

[NightBeast]

I bought a Panasonic DP-UB820P-K in January 2022. I recently noticed I get weird playback glitches when using Dolby Vision. My TV and HDMI cables are Dolby Vision compatible. Streaming Dolby Vision on the Panasonic is fine. But UHD playback with Dolby Vision causes white flashes/pixels on the far left edge of my screen even during menus and startup. Turn off Dolby Vision and its fine. I’ve seen this so far on Raiders of the Lost Ark, The Last Crusade, Kingdom of the Crystal Skull, Godzilla vs. Kong, and The Wizard of Oz. Panasonic tech support says it’s my machine that’s faulty, which seems odd. The firmware is up to date. I’ve tried resetting and reinstalling the firmware. Has anyone else encountered this problem?

 

[Clinton McClure]

Is your HDMI cable certified 18Gbps or higher? If not, I would suggest trying a different cable that is.

 

[NightBeast]

Thanks! It’s an Audioquest Pearl 48, certified at 48 Gbps.

 

[Clinton McClure]

Are you still within a return window where you could swap the 820 for a new one?

 

[NightBeast]

I tried a replacement Audioquest Pearl 48 HDMI cable. It still showed glitches with Dolby Vision. I swapped it out with an Amazon Basics cable. No glitches! Great. I confirmed the Panasonic was still sending a Dolby Vision signal (the Panasonic wouldn’t let me use the “HDR Settings” button due to Dolby Vision, and my Sony Bravia OLED TV says it was receiving a Dolby Vision signal), so it’s not like the Amazon Basics cable was somehow downgrading the signal. I feel like the picture quality wasn’t quite as good with the Amazon cable, but it sure is nice to not have random white flashes on the screen.

 

[Clinton McClure]

I tried a replacement Audioquest Pearl 48 HDMI cable. It still showed glitches with Dolby Vision. I swapped it out with an Amazon Basics cable. No glitches! Great. I confirmed the Panasonic was still sending a Dolby Vision signal (the Panasonic wouldn’t let me use the “HDR Settings” button due to Dolby Vision, and my Sony Bravia OLED TV says it was receiving a Dolby Vision signal), so it’s not like the Amazon Basics cable was somehow downgrading the signal. I feel like the picture quality wasn’t quite as good with the Amazon cable, but it sure is nice to not have random white flashes on the screen.

Something to keep in mind concerning picture quality via HDMI. Since it’s a digital connection, there is no signal degradation like used to happen with analog RCA cables. You are now just moving 1s and 0s and the signal is either on or off. There is no in-between. A $200 HDMI cable will not give you a better image than a $10 HDMI cable. I personally use Monoprice cables rated at 18Gbps and have flawless HDR and DV on all my devices. I think I paid less than $10 per cable. Really cheap and poorly built cables, or cables that are not rated at a fast enough bandwidth, may exhibit sparkles or weird issues like you were observing.