arc not waking out of standby LG C1

Is the firmware of everything up to date? I would also reboot the LG. too. A strategy that has improved things in other situations is to disconnect all HDMI’s to the TV, power down both units for a few minutes, then power-up the TV and ARC and then reconnect their HDMI cable. The TV and ARC will rediscover each other. Now you can connect other HDMI devices, if any. Make sure that the HDMI cables are fully seated in their sockets.

In situations such as this it is hard to place blame without using some very expensive test equipment. There could be an anomaly in either the LG, ARC, or the HDMI cable. Replacing the wrong unit may not cure the issue.

Do I understand correctly, you recently changed the TV?

It’s always been the LG tv… the issue has been happening since the tv and arc were purchased about a year ago. The setup is just the LG C1 , arc, and a comcast Xfinity top box. I tried the unplug hdmi and power for everything earlier tonight and will see if that works, I also ordered some newer ultra hdmi cords. From what I can tell, the arc just doesn’t get the signal to wake up after things have been shut down overnight. 

I also turned off the quick start setting or whatever it is today… we will see. 

Which power button are you using to turn ON the system? It may help if you use another power button.

Quick start disabled, will just cause your TV to take longer to power on - I would check and disable CEC control on all the devices connected to HDMI ports 1, 3 and 4 (if relevant) and leave the Sonos Arc to get CEC focus.

Also toggle off/on (and leave on) TV Autoplay in ‘Settings/System/[Arc Room Name]’ in the Sonos App and see if those few things fix the issue.

None of the above fixed it… I came down this morning and powered everything up and the Sonos is still asleep. No white or green light in front after turning on the tv. I also went into the Sonos app and the system does not show up there… is that normal for when it is in in standby?

 My last thing to try is newer hdmi cords. Other than that I am out of ideas. 
 

It’s certainly is not normal …and the fact the Arc is not showing up in your Sonos App, is ‘inferring’ it’s not the HDMI cable either.

Did you switch off CEC on your ‘other’ connected devices and toggle the ‘TV Autoplay’ feature? 

It would be interesting to see if the issue goes away if you disconnect all other devices connected to HDMI ports 1, 3 and 4 - I would do that just to eliminate the possibility that another device is stealing the CEC (‘Simplink’) focus away from HDMI-2 (ARC/eARC) port.

The drop from the App though is another issue entirely - are you running the setup on ‘SonosNet’ or on your local WiFi? Is the WiFi a mesh-setup, or central router (with or without additional wireless access points) Are the access points wired back to the router?

More info is needed to know exactly why the Arc is not being discovered by the App.

What mobile device are you using as your Sonos controller?

So the arc should still show on the app when it is in standby or sleep mode? It is a mesh orbi wifi and everything is wireless, no Ethernet. I have never had issues with the wifi it’s been very reliable, my app controller is my iPhone. 
 

and yes I have toggled tv auto play. I just plugged in the new hdmi cords and will disconnect the cable box from hdmi 1 when I shut everything down tonight overnight. 
thanks 

There is often issues with Orbi Hubs operating on different channels and not allowing the discovery of SSDP multicast packets between the 5Ghz Band and 2.4Ghz band - the Arc will always connect using the 2.4Ghz band - so my suggestion is to follow the advice in this Sonos Staff initiated thread:

Sonos on WiFi Mesh
 

I would personally suggest switching your system over to SonosNet - that entails wiring a single Sonos device (not a HT surround or sub) to the primary Orbi hub/router. Do not wire any Sonos devices to the Orbi Satellite hubs. Keep the wired Sonos product at least one metre away from your Orbi hub, or other wireless device.

See this helpful support page too:

https://support.sonos.com/en-us/article/switch-sonos-between-a-wireless-and-wired-setup
 

When the above is in place, remove the Orbi WiFi credentials from the Sonos App network settings (Note only do this step if you do not own any Sonos portable products - Roam/Move).

Finally set the SonosNet channel to one not in use by your Orbi Hubs.

Those step should then stop the issue your are having with the Sonos App discovering your devices.

Sort that first and then post back, as we still need to resolve the TV autoplay issue, which I still think will likely be a CEC discovery issue and ‘perhaps’ a different matter to your discovery issue, although wireless interference cannot be ruled out at this stage.

I should add the above post assumes your (ISP Provided?) original modem/router is ‘bridged’ and the Orbi mesh setup is operating in ‘router mode’ and that the Orbi setup itself, is not ‘bridged’ and all hubs acting as AP’s to your ISP router/modem - If the Orbi system is in ’bridged AP’ mode you will need to wire the Sonos product mentioned to the router instead (which should have its own WiFi adapters disabled).

Hope that assists.