BK 402A Not Sending Audio to Sonos Soundbar

Seems like the Sonos Arc hasn’t made a handshake with the projector yet. I’d try a power cycle of both.

If that doesn’t work, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, Sonos’ lawyers get sensitive about GDPR, I suspect.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

The Optoma UHD38x doesn’t have an eARC/ARC port.  It only has HDMI.

Wait. I’m rereading your post, and there is some things I don’t understand.

I connected the projector to OUT1 (eARC) on what?

 Sonos soundbar to INPUT eARC on what?

I’m pretty sure the OP means the eARC in/out ports on the BK 402A switch.

Aha. The BK402A is this OREI device. That explains a lot. What did OREI’s customer support say?

From: https://www.crutchfield.com/S-qcXA8Pp6hWQ/p_343UHD38X/Optoma-UHD38X.html?XVINQ=D74&XVVer=CFN&awcr=657192960168&awdv=c&awnw=g&awug=9002019&awkw=dsa-2096179776717&awmt=&awat=&gad_source=1&gad_campaignid=18788752269&gclid=CjwKCAiAtLvMBhB_EiwA1u6_PuJMwLsmZ700mmx6N2F_KiyUv8EqGvd43EXrtnH3jgTAU07o8X0I-BoCbh4QAvD_BwE

Connections
HDMI Inputs	2
HDMI Version	2.0
Audio Return Channel	No

Yea, the page I linked to suggests some eARC support on a few of the ports, but as this isn’t really a Sonos issue, but an OREI issue, I didn’t look very far ;)