LG 48" OLED - Erratic HDMI Performance

Quotidian

Novice Member
I bought a 48" LG OLED TV in late 2021. Overall it's a good product with good picture quality and performance. However the HDMI performance is erratic.

I have the following units attached to HDMI ports - Hisense Soundbar (HDMI1), Apple TV (HDMI2) and Facebook Portal TV (HDMI3)

However, the HDMI connection to the Soundbar works very erratically. Quite often the TV and Soundbar will start up with no problems, and the speaker respond to the LG Smart Control just as it should.

However, other times the TV will start up with the TV Speaker selected for sound. When it does that, selecting the Sound Bar will produce no sound, even if the Soundbar appears to be powered on. If this happens and if you select the Soundbar using the Settings button on the Control, there is no sound from the Soundbar, and then depress the volume control, a mute icon appears on-screen while the control is pressed. It seems some kind of software conflict.

Sometimes I will start up the system by using the Apple TV remote, which sometimes seems to initialise the HDMI sequence correctly so that the TV-Soundbar combination works. But not always.

It's obviously not an enormous issue but a niggling problem. Anyone got any tips?
 

next010

Distinguished Member
The feature your having problems with is called HDMI-CEC (LG brands it as Simplink), unfortunately CEC is not a strict uniform standard so is implemented differently in devices leading to the issues your having.

The only way LG could actually fix it would be to test the same hardware and iron out the differences in the CEC chain.

Run the universal remote set up in WebOS and tell it a Hisense soundbar is attached, this may program the LG magic remote with commands that the bar might more reliably respond too but it may be a compatibility issue that cannot be resolved.

Lastly try manually powering on the soundbar using its own remote before turning on the TV that might give the TV time to correctly see the soundbar.
 

Quotidian

Novice Member
thanks. I've tried all those techniques but it really seems a lucky dip whether the startup cycle works properly. I suspect that TV operating systems aren't nearly so reliable as computer and mobile versions. But the fact that it's branded Simplink by LG might help as I can google down on some specific queries. I suppose I can also try using the optical cable option for the Soundbar, that might work. If I find a solution I'll post it.
 

PlexShaw

Well-known Member
On my 48" LG C1, the ARC/eARC port is HDMI 2, so that's where my Sony soundbar is connected to for audio to work properly. Perhaps that's the issue with your setup?

Regarding the CEC thing, I recently purchased a Lindy HDMI CEC Blocker adapter for the Apple TV 4K connection as, even with it switched off in the ATV menus, it was interfering with the soundbar connection.
 

Quotidian

Novice Member
Perhaps that's the issue with your setup?
There's a port in the back of the LG TV which is specifically labelled HDMI (ARC) which is for soundbars, so that's not it. But you might be on to something with the Apple TV as I've learned it's not CEC compliant, I'll look into that.
 

Quotidian

Novice Member
Lindy HDMI CEC Blocker adapter for the Apple TV 4K
I've just looked into the info for a product called "Lindy HDMI CEC Less Adaptor", that appears to be the product you're referring to. So, do you put this adaptor between the Apple TV cable and the input socket on the LG TV?
 

next010

Distinguished Member
The AppleTV does support CEC, they brand it as control AV devices under the settings\remote section of the device, you can toggle it on/off there.

Using the Lindy adapter will disable the HDMI pins that send CEC commands, you will lose all control via CEC so no auto power on/off volume etc.
 

next010

Distinguished Member
If the Hisense soundbar was a low cost model, you might want to consider replacing it with an LG soundbar if you can afford it.

If the Hisense soundbar was an expensive model, there is the Sharc which is an eARC/ARC bridge for sound systems, this will replace the CEC/ARC system, so Sharc goes to ARC port on TV and its output goes to the HDMI input of the soundbar and the Sharc controls the bar via CEC.

It's nots guaranteed to resolve the problems though the Sharc was developed with LG TV's but its still cheaper than buying a new high end soundbar.

Maybe there are cheaper solutions to replacing the CEC/ARC output out there.
 

Quotidian

Novice Member
Meh. I think I’ll just live with what I’ve got. It works most of the time, and that’s as good as it gets
 

PlexShaw

Well-known Member
I've just looked into the info for a product called "Lindy HDMI CEC Less Adaptor", that appears to be the product you're referring to. So, do you put this adaptor between the Apple TV cable and the input socket on the LG TV?
I just plugged the adapter into the back of the Apple TV and then plugged the HDMI cable into that. Although there is a toggle to switch off CEC in the Apple TV settings area, I found this doesn't work fully/correctly and that using the CEC blocker was the only way to get around that. I don't mind that it disables it completely as I don't use the functionality on anything attached to my TV other than the soundbar.
 
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