4KTV screen flickers black rapidly when Deep Color RGB is enabled on TV

[Ransome]

Got a 4K TV recently.
Connected my PC with a 10 meter Hugh Speed HDMI cable directly to port 3 of the TV (using a 90° adapter).

3840x2160 4K 60Hz works , 1080p 60Hz works.
1440p 2K - 2560x1440 doesn't work at 60Hz- only 30 Hz in games a d that sucks!! ANY IDEAS?

Now once I enabled Deep Color on my LG TV for this HDMI3 port - the entire image was going haywire , blinking at a rapid pace, or going full black, mostly just flickers fast.
Only way to stop this was disabling the HDMI Deep Color (RGB or "true color") setting on the TV itself - because I can't control the PC with that flicker.

Lastly I wasn't able to get 5.1 surround audio when my PC was directly connected to the TV , and TV to the AVR with HDMI ARC (port #2) (or with Optical). Problem is that Windows 10 Sound Settings detects my TV and offers only stereo.

So to sum up, 3 major issues :
1. Deep Color - and thus RGB and HDR as well -makes my 4K TV screen to flicker rapidly - But only with the PC! Works well with my PS4 and even PS3.
2. 1440p works at only 30 Hz, even when set in game. Hownto get that to 60Hz?
3. PC - Sound Settings - only detects Stereo 2.0 when connected directly to PC.


GTX 989 SLI
Pioneer VSX 823
LG B6 OLED65 (might replace it to Samsung KS8500)

Thanks

 

[Gmanuel]

I have the 55" B6, so I may be able to help. First, why do you have such a long run between your tv and tower? 30 meters is the max length for HDMI 2.0 standard, so you might try moving the PC closer and using a shorter run cable. Second, make sure you're using a "High speed", or 18Gbps cable.
You said you used audio over the ARC port, but have you tried switching to an optical cable for audio?
When I was experiencing similar issues I found that HDMI 1 and 2 would flicker at RGB, and 4:4:4, but HDMI 3 and 4 had no problems. I also switched from ARC to optical. I'll test using port 3 and ARC on my machine today, and report back.

Edit: Your post says you run 980sli, correct? Are you able to confirm your 980s have HDMI 2.0 ports?

 

[Ransome]

I have the 55" B6, so I may be able to help. First, why do you have such a long run between your tv and tower? 30 meters is the max length for HDMI 2.0 standard, so you might try moving the PC closer and using a shorter run cable. Second, make sure you're using a "High speed", or 18Gbps cable.
You said you used audio over the ARC port, but have you tried switching to an optical cable for audio?
When I was experiencing similar issues I found that HDMI 1 and 2 would flicker at RGB, and 4:4:4, but HDMI 3 and 4 had no problems. I also switched from ARC to optical. I'll test using port 3 and ARC on my machine today, and report back.

Edit: Your post says you run 980sli, correct? Are you able to confirm your 980s have HDMI 2.0 ports?

Hey, thanks for the answer.
Well, I am going to try connecting the TV with Optical now and see if the PC detects 5m1 surround option, but I highly doubt it. There's no chance.
Do you have 5.1 or 7.1 Speaker Surround when you PC is connected Directly to a TV and the TV itself is connected to a AV-Reciever with Optical?

Read about it and it seems that the ONLY way to enjoy 5.1 Surround with 4K 60HZ is having your PC routing through a 4K HDCP 2.2 AVR- meaning the PC connected to AVR which is connected to TV. AVR being a HUB and must be HDMI 2.0, hdcp 2.2 and 4k60hz supporting.

My cable is a high quality (I believe) HIGH SPEED HDMI WITH ETHERNET.
It's very thick. 10 meters because my PC is sitting in my bedroom and my Home Theater 5.1AVR +TV are located across the wall on the far wall of a different and adjacent room - the living room.

As far as I recall - all cards since Maxwell 960 (including 980) support HDMI 2.0 and HDCP.

What was that about RGB and 4:4:4 ? Which ports worked best? And do you set FULL or Limited? What about the 4:4:4 or 4:4:2 etc ? Which one are you using and why? Can't solve the damn flicker.

 

[Gmanuel]

Just tested everything on my machine. To be clear, the 55" variant has HDMI 1&2 on the side, parallel with the panel. HDMI 3&4 are on the back, with the cables connecting at a 90° angle to the panel. Does the 65" have the ports numbered the same?

With video coming straight from my PC to HDMI 3, and audio running straight from my 5.1 sound system to HDMI 2, I am able to use RGB/8bpc/Full dynamic range with 4k @ 60Hz. When I disable deep color mode on HDMI 3, I of course have to drop down to limited. 4:4:4 only gives me the option for 8bpc.
I think the main difference between our setups is you have an AVR in the middle. It may not work exactly as you would like, but I'd try removing that from the equation just for the sake of troubleshooting.

 

[Ransome]

Just tested everything on my machine. To be clear, the 55" variant has HDMI 1&2 on the side, parallel with the panel. HDMI 3&4 are on the back, with the cables connecting at a 90° angle to the panel. Does the 65" have the ports numbered the same?

With video coming straight from my PC to HDMI 3, and audio running straight from my 5.1 sound system to HDMI 2, I am able to use RGB/8bpc/Full dynamic range with 4k @ 60Hz. When I disable deep color mode on HDMI 3, I of course have to drop down to limited. 4:4:4 only gives me the option for 8bpc.
I think the main difference between our setups is you have an AVR in the middle. It may not work exactly as you would like, but I'd try removing that from the equation just for the sake of troubleshooting.

You should still be locked to 2.0 stereo. Are you not? You do have a Reciever?
Edit: ok I am guessing you an independent 5.1 pc speaker systemlike Creative's/Logitech connecting to your motherboard's sound card on the pc, with standard speaker cables (green black orange )?

AVR- whether hdmi or optical - only give 2.0 stereo if PC connected directly to the TV and TV sends audio to AVR.
If I am mistaken please show me.
There's no way to have true 5.1 surround audio without connecting the PC to a 4K AVR and the AVR to the TV. Other option is sending optical from PC to AVR that's far less practical.
Already ordered a 4K 60fps hdcp 2.2 AVR. Got the Onkyo TXNR 555. Best bang for buck gaming Receiver out there for the price. Hoping I am getting a good unit becauseI am shipping internationally.


About Ultra HD Deep Color ON problems with flicker/no signal:

Just tested it connecting PC directly to HDMI 3 without the 90° adapter made Dee Color work and RGB FULL available as well as 444 422 amd 420.
It worked without a hitch it seems. That's great and works like you said...
However connecting the same cable to HDMI 1 and HDMI 2 with Deep Color On made the screen goes solid black with "Unsupported Fotmat" message by LG and momentarily flicker image for brief seconds.
So it seems HDMI 1 and 2 do not support RGB and hdmi 2.0 with PC and 2.0 GPUs. That's quite unacceptable. Not good.
Plus I just found 2 dead pixels, one on the top 1/5 and one on the bottom 1/5 and I have the TV for 3-4days basically.

65 has the same ports as the 55.

So to conclude...Not full RGB True Color support. Problems with cables 5 meter and higher. Image retention. Dead pixels off the bat. Bugs with connectivity of all kind... and all that for a premium price.
That makes me want to demand a refund and ordwr a Samsung KS8500 65 first thing next morning. Disappointing and frustrating.

 

[Gmanuel]

Ouch. Yeah, I might try returning it if you have dead pixels. HDMI 1 and 2 on mine have the same issue with flickering in deep color mode, but no dead pixels or any other issues, so I'm happy enough.
Maybe I'm not getting true 5.1, I need to test this out now that you mention it. I'd hate to be losing out on sound quality.
Glad we got the flickering part figured out, but I can't help you with the sound until I'm sure I'm getting true 5.1 myself lol I wish you luck with it though