LG G4: Random no sound/black screen flicker

[MrWinn]

Recently changed TV to a new LG G4 65" (2024 model), with an LG soundbar.

Since changing the TV anything we watch from Sky Q 2TB v3 set top box (hardware version 32B206), we get 2 issues:-

1) Random no sound for up to a second 

2) Random Black screen flicker for about half a second.

note: these DO NOT normally occur at the same time. 

It can be up to 30 mins between the issues occurring, or it can be a few minutes.

No issues watching with Apple TV 4K, watching 4K streaming like Netflix, Apple TV etc.

I have switched HDMI port with the Apple TV,  changed HDMI leads for expensive ones, performed a reset settings and even forced an update, but the issues still occurs.

Assuming it's not a TV issue if Apple TV works OK.

Anything else I can try, before I ring Sky?

Moderator note: added 'LG G4' to title so more users can find thread

[Mazagoon]

Did you find a solution to this problem. I am having the same issue and have turn off deep colour. Not sure if this has fixed it yet but if you have an official fix from sky I would be grateful to hear it 

[MrWinn]

@Mazagoon Not yet, still to report it to Sky,

Your deep colour change was that on TV or Sky box?

[cuke]

Personally I'd also report to LG. The G4 was released with a HDMI issue which was resolved by a firmware update. However for some LG introduced other bugs, sound dropouts and blackouts similar to what is being stated in this thread here. This is the thread that reported such issues

https://www.avforums.com/threads/lg-oled-g4-hdmi2-video-issue.2494503/page-9

[Mazagoon]

So, I called LG and Sky again because the issue persisted. Both companies offered assistance, but nothing seemed to resolve it. I also reset my TV and Sky box, which I had done before. This time, when my Sky box previously appeared as a Vodafone Set Top Box, it changed to a Sky Set Top Box. And guess what? It finally worked! The universal remote could now control the Sky box, which it hadn’t done before. It turned out that there was some kind of handshaking issue, and this had resolved it. Since then, my problem has completely disappeared! 

[Mazagoon]

Also, and I don't want to teach grandma to suck eggs, but make sure you turn off the TV and switch it off at the wall before you add any HDMI cable to the ports on the TV. Add the HDMI while to Sky box is without power then turn the TV on and then the Sky box. 

[Simonb73]

I've been having the same issue since I got the new Sky Q box. On my old LG I had to unplug the HDMI as it wouldn't get a signal when started up. On my new LG G4 this problem persists along with sound and picture drop outs. 

All new HDMI leads and my 2nd Sky Q box. 

I have noticed these are minimal when the Sky Q box is switched to 8-bit. 

[Mazagoon · Accepted solution]

It is definitely a handshaking issue and it seems to have stopped completely on my LG G4. I reset the box and the TV, plugged in all cables while the TV was off and unplugged.  Then turned the TV on and after initial setup and before running universal control setting, turned the sky box on. This recognised the sky box and I ran through all of the settings to allow the Sky box to be controlled by the TV remote. As long as the TV recognises the Sky box as as Sky box and allows you to control the box using your TVs remote the problem should not occur. Previously this was not the case. If you are unable to control the Sky with your TV remote it has not connected properly and this causes a handshaking incompatibility which also then causes the sound and picture to flicker and dropout. I hope this helps. As I have said since following these steps I have not had the problem at all. 

[Simonb73]

Thanks for the info. I have done this and the TV remote does control the Sky Q box. Not sure if it did before. 

I will monitor. 

[Simonb73]

Still no good. Sound drop outs watching a downloaded Film in HDR. Everytime it did the Dolby Atmos banner came up in the corner of the screen. Didn't notice the picture dropping. Turned it on today and no HDMI signal again. Switched the Sky box back to 8-bit. 

[Mazagoon]

Which HDMI port have you got your Sky box plugged in to? Do you use a 2.1 HDMI cable? Sky only supply a 2.0. When I spoke to LG they suggested it was plugged in to HDMI one and that a 2.1 cable was used. 

[Mazagoon]

I think also they Sky suggested making sure that audio was set to PCM. Are you using a sound bar? 

[Simonb73]

Hi. Thanks for the reply 

Using HDMI 1 for Sky and HDMI 2 for sound bar LG USG10TY. All new HDMI 2.1 leads. 

Had no sound drop outs this afternoon when UHD is set to 8-bit on the Sky Q box. 

[MrWinn]

After resetting back to factory settings and running through the initial setup, no issues in the last 24 hrs.

[Simonb73]

Are you referring to the TV or Sky Q box?