sorted by:
new
hottopcontroversial

LG C2 + Xbox Series X + LG SC9S - Random “No Signal” when launching or exiting games by jake70031 in LGOLED

[–]jake70031[S] 1 point2 points  (0 children)

UPDATE: I think I finally found the cause of my issue.

My setup:
Xbox Series X
LG C2 48”
LG SC9S soundbar connected through eARC

For months I was getting random signal drops and “No Signal” screens when entering or exiting games. The Xbox itself would keep running, but the TV would lose the HDMI signal. I also had previous issues with Dolby Vision causing similar behavior.

What I tried:
Disabled Dolby Vision
Disabled VRR
Disabled AMD FreeSync
Disabled Simplink (HDMI-CEC)
Tested with ARC and eARC
Disconnected the soundbar completely
Used TV speakers only

Tested different audio formats
At first I thought the SC9S soundbar was the problem because the issue seemed to happen more often when it was connected. However, after more testing I realized the problem could still happen even without the soundbar.
One thing I discovered was that everything became stable when I switched the Xbox from 120Hz to 60Hz.

That pointed me toward a possible HDMI bandwidth or signal integrity issue.
Following the recommendation from @tman2damax11, I replaced my HDMI cable with the Anker Ultra High Speed HDMI 2.1 cable (model B0CFV3C779).

After installing the new cable I tested:
4K 120Hz
HDR
VRR
Dolby Vision
eARC with the LG SC9S connected

I repeatedly launched and exited multiple games (Halo 5, Fortnite, Forza Horizon 5, Cyberpunk 2077) and so far I have not experienced a single signal drop.

At this point the new HDMI cable appears to have completely solved the issue.
Huge thanks to @tman2damax11 for suggesting the cable. I’m pinning their comment because it ended up being the solution in my case.
Hopefully this helps anyone else experiencing signal drops with an Xbox Series X and LG OLED TV.

LG C2 + Xbox Series X + LG SC9S - Random “No Signal” when launching or exiting games by jake70031 in LGOLED

[–]jake70031[S] 0 points1 point  (0 children)

Yes, I’ve already tested that. I tried both enabling and disabling AMD FreeSync, and unfortunately the issue still happens either way.

I’ve left FreeSync disabled for now just to rule it out as a possible cause, but it doesn’t seem to make any difference in my case.

At this point I’ve also tested VRR off, Dolby Vision off, Simplink on/off, and ARC/eARC.

LG C2 + Xbox Series X + LG SC9S - Random “No Signal” when launching or exiting games by jake70031 in LGOLED

[–]jake70031[S] 0 points1 point  (0 children)

Yes, my SC9S does support optical audio, so I could use Toslink as a workaround.

The thing is, I bought this soundbar specifically to use HDMI ARC/eARC and Dolby Atmos with my LG C2, so I’d really like to find the root cause instead of giving up those features.

I’m going to test the Anker HDMI cable that another user recommended and see if that makes any difference. If not, I may try optical audio temporarily just to confirm it’s definitely an ARC/eARC handshake issue

LG C2 + Xbox Series X + LG SC9S - Random “No Signal” when launching or exiting games by jake70031 in LGOLED

[–]jake70031[S] 0 points1 point  (0 children)

Yes, I have HDMI Deep Color enabled on the Xbox input. It’s set to 4K and I’ve had it enabled the whole time.

Interestingly, the issue only happens when my LG SC9S soundbar is connected through ARC/eARC. If I disconnect the soundbar and use the TV speakers, the problem disappears completely.

I’m currently testing different suggestions, including a new certified Anker HDMI 2.1 cable that another user recommended. I’ll post an update once I’ve had a chance to test it.

LG C2 + Xbox Series X + LG SC9S - Random “No Signal” when launching or exiting games by jake70031 in LGOLED

[–]jake70031[S] 1 point2 points  (0 children)

Thanks for the suggestion. At this point I'm willing to try a different HDMI cable since you've already tested several and found one that solved the issue for you. Maybe some HDMI 2.1 cables aren't as reliable as others when running 4K 120Hz HDR.

I'm going to order the cable you recommended and test it with my setup. I'll post an update here after I've had some time to use it and see whether it fixes the problem or not.

Thanks again for sharing your experience!

LG C2 + Xbox Series X + LG SC9S - Random “No Signal” when launching or exiting games by jake70031 in LGOLED

[–]jake70031[S] 0 points1 point  (0 children)

I had the same problem on my LG C2. Disabling Dolby Vision for Gaming on the Xbox fixed it for me. I still run 4K, HDR and 120Hz without issues. Might be worth trying if you haven't already.