Denon X1800H + LG C5 + Shield/PS5 - CEC power & input switching broken after working fine
Denon X1800H + LG C5 + Shield/PS5 – CEC power & input switching broken after working fine
Looking for help diagnosing HDMI-CEC / power and input switching issues in my setup.
Gear:
TV: LG C5 OLED TV (87")
AVR: Denon AVR-X1800H
Sources on denon: PlayStation 5 + NVIDIA Shield TV
Everything was working perfectly before—CEC power on/off and input switching were reliable. Then suddenly it stopped behaving properly.
Current issues:
Power on/off (CEC) is inconsistent.
Turning on a source (PS5 or Shield) doesn’t always power on the full chain.
Sometimes TV or AVR stays off, or turns on without syncing correctly
Input/source switching is unreliable
AVR sometimes switches to the correct input when a device turns on
Other times it either doesn’t switch or switches incorrectly.
Behavior feels random/inconsistent
System “confusion”.
Devices don’t seem to agree on active source
Occasional mismatches between what’s on and what input is selected.
When I turn on the shield the tv doesn't always turn on.
What I’ve tried:
Swapping HDMI cables, using 8k certified between all devices now.
Power cycling all devices.
Checking HDMI-CEC settings (Simplink on LG, HDMI Control on Denon).
Tried many different settings in every device.
Is this typical HDMI-CEC instability, or something specific to Denon + LG setups?
Any better “known stable” config (e.g., only one device controlling power)?
Would a full reset of the Denon AVR-X1800H help, or better to isolate first?
Could firmware or a stuck HDMI handshake state cause this sudden change?
Trying to decide whether to keep fighting CEC or just move to a universal remote setup.
Getting crazy with this setup and I believe the denon is the problematic one (I have a similar setup with a Sony receiver and it works perfectly)