NUC CEC Issue — LG WebOS 4.0 (SW Version 05.10.25, November 2019)

Modified on Thu, 30 Apr at 11:04 PM

On LG TVs running WebOS 4.0 with software version 05.10.25 (released November 2019), CEC does not function on HDMI 2 — the port labelled ARC. This is a known firmware issue specific to that LG software release and is not caused by the NUC-CEC adapter or libcec.

Symptom

CEC commands from your NUC are not received by the TV when the NUC is connected to the HDMI 2 (ARC) port. Other HDMI ports on the same TV may work correctly. The issue only affects this specific LG firmware version.

Fix

Connect your NUC to HDMI 1 instead of HDMI 2. CEC communication will function correctly on HDMI 1 on this firmware version.

Power off the NUC and TV. Disconnect the HDMI cable from the HDMI 2 (ARC) port on the back of the TV.

Connect to HDMI 1. Plug the HDMI cable from your NUC (or NUC-CEC adapter) into the HDMI 1 port on the TV.

Power on and test. Boot the NUC and confirm CEC commands are working — for example, verify the TV turns on and off via CEC Tray or cec-client.

If you update your LG TV's firmware to a version newer than 05.10.25, check whether HDMI 2 CEC functionality has been restored. You may be able to move back to HDMI 2 after a firmware update.

Affected Configuration

This issue affects LG TVs with all of the following:

Operating system: WebOS 4.0
Software version: 05.10.25 (released November 2019)
Port affected: HDMI 2 (labelled ARC)

Still not working after switching to HDMI 1?
Contact Pulse-Eight support with your LG TV model number and software version.

UK: 01202 413 610 | US: (858) 748-8250 | support@pulse-eight.com

NUC CEC Issue — LG WebOS 4.0 (SW Version 05.10.25, November 2019)

Symptom

Fix

Affected Configuration

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