4k TV won't display anything from my PC

Brumboy · 24 Dec 2020 at 14:07

Merry Christmas Eve everyone!

I'm trying to simply connect my PC upstairs to my TV downstairs. The TV is Sony X900F. I'm using a HDMI cable from the 3070 HDMI port to the HDMI port on my TV.

This worked fine a few weeks ago but ever since I've upgraded my PC it hasn't.

The TV is HDR.

No matter what combination of display settings, refresh rates, scaling or most other settings the TV just simply does not display anything from my PC. It is driving me mad having spent about an hour already on this.

Could you please help me! Thank you

Brumboy · 24 Dec 2020 at 14:19

I have only one cable that is long enough for this connection (20M)

Brumboy · 26 Dec 2020 at 12:56

It worked before when I had a 2080. I upgraded my PC and now this has happened. I was able to have 4k, 60hz and HDR working with the cable before the upgrade so it can't be the cable.

I have managed to get it to display but only when I change the HDMI signal format setting to "standard" on the TV, but this results in a fuzzy picture with off colours and I cannot change the Output colour format to anything other than YCBCR420.

Really confused to be honest! I need it to work with the "enchanced" HDMI signal format somehow.

Brumboy · 26 Dec 2020 at 14:45

I understand this but how does that explain the fact that I was able to enable HDR, 10 bit, 4k, 60hz when using the same cable from my PC to the TV before? It definitely worked.

Now it doesn't. Although after further research some people have had this same issue after the latest update for the TV, so I think that may be the issue. Bit annoyed as you cannot rollback TV updates!

The cable is definitely 18Gbps. I don't have another 4k HDR display to test it on but if it is the TV update then that's a pain in the arse!

Would a shorter cable such as 10M paired with some kind of HDMI repeater/booster work?

Brumboy · 26 Dec 2020 at 15:39

lucid said:
Well, if it is truly 18Gbps then it should work.

Are you trying to send RGB (4:4:4) down the cable? Have you tried Component ((4:2:2 or 4:2:0)?

I don't get those options in Nvidia control panel. I think they only appear if the HDMI Enchantment mode is set on the TV but if I do that there is no signal at all from the PC

Brumboy · 28 Dec 2020 at 10:29

I ordered three new cables and tested them all. 2 of them worked fine. No idea why the original cable stopped working all of a sudden but oh well at least it's solved.

Thankfully I can return the original cable. The two that worked have a chipset device mid way through the cable, about 5M in. should have ordered this kind of cable originally!

Thank you all for the help!