Unable to run Samsung JU6700 @ 4:4:4 60 Hz with GTX 950??

[patterrr]

I'm a long time reader but a first time poster, as usually I can solve my issues reading but not this time...

I have a new Samsung UN40JU6700 TV that I'm using as a monitor and a GTX 950 (specifically a Zotac ZT-90601-10L). From everything I've read on other threads, this should support 4:4:4 @ 60 Hz. However, I'm not having any luck.

Out of the box, 4:4:4 at 3840 x 2160 @ 30 Hz works just fine. So then I switch it to 60 Hz using NVIDIA Control Panel. This makes the text look strange, with colored and blurry edges. I then go to Picture Options on the TV and change it to UHD mode. The TV reboots, and says no signal. Of course the TV also says this if I try 30 Hz.

I'm running Windows 7 64-bit SP1, and NVIDIA driver version 361.91. I'm using a brand new Monpoprice HDMI cable, specifically the 13758. Oh, and I'm using HDMI In 1 on the TV, supposedly that's the only HDMI port that supports UHD.

I've tried everything I can think of. Has anybody else had any luck with this combination? Thanks!

 

[Suzuki@1473780084@1473780163]

Is "PC mode" enabled in the TV's menu, while you try this?

 

[patterrr]

Is "PC mode" enabled in the TV's menu, while you try this?

Yes, with the remote, I clicked source, dropped down on HDMI 1 (the currently active source), and then selected Type, and "PC" is checked. Thanks.

 

[Suzuki@1473780084@1473780163]

That's odd. In PC mode, it should allow 4:4:4. I can't think of any reason why that wouldn't work, as it's the only mode which lets you use 4:4:4.

Page 25 in your manual: http://downloadcenter.samsung.com/content/UM/201512/20151210090904492/ENG_US-HMUATSCJ-1.318-1203.pdf

Is that what you did?

 

[Suzuki@1473780084@1473780163]

If you think you did everything right, then try 4:4:4 using this image: http://www.avsforum.com/attachments/9759

It's a .zip file. You want to view this image, and if you are able to read the text in the bottom two lines, the ones with a red and blue background, then you are using 4:4:4.

To clarify something you mentioned in your OP, which is why I never bring this up. Is this what you did when you said "UHD mode": http://support-us.samsung.com/cyber/popup/iframe/pop_troubleshooting_fr.jsp?modelname=&homeid=543454&from_osc=&idx=545582& ?


If neither of these work, then I suspect the HDMI cable, and it would be a first time seeing this.

 

[patterrr]

If you think you did everything right, then try 4:4:4 using this image: http://www.avsforum.com/attachments/9759

It's a .zip file. You want to view this image, and if you are able to read the text in the bottom two lines, the ones with a red and blue background, then you are using 4:4:4.

To clarify something you mentioned in your OP, which is why I never bring this up. Is this what you did when you said "UHD mode": http://support-us.samsung.com/cyber/popup/iframe/pop_troubleshooting_fr.jsp?modelname=&homeid=543454&from_osc=&idx=545582& ?


If neither of these work, then I suspect the HDMI cable, and it would be a first time seeing this.

Thanks for your suggestions, Suzuki. The instructions that you linked are precisely how I switch to / from UHD mode. When UHD mode is off, the monitor works at 30 Hz & 60 Hz (but with the colored / blurry text edges); when I turn UHD mode on, the TV restarts and says no signal. The only way to restore it is to turn that mode back off. I am kind of surprised that UHD mode won't pick up a 30 Hz signal, that means I can't use this monitor for BIOS settings, boot messages, etc. when I do eventually get it working.

To answer your other question, I can clearly read the text (including the bottom two lines with colored backgrounds). If I switch it from 4:4:4 mode to RGB I can still read the bottom two lines... I guess this just indicates that it isn't running 4:4:0 mode.

I assumed I am doing something wrong, or my hardware isn't compatible. You might be right, maybe it is the cable. If nothing else comes tomorrow I'll order another one to test out.

Thanks.

 

[Suzuki@1473780084@1473780163]

But if its not the cable then that's wasting money. You should try Samsung live chat, though since you passed the test, it's in 4:4:4, otherwise you wouldn't be able to read it.

 

[patterrr]

Given the value of my time and the frustration of customer service, I decided to try another cable - I figured it would be $5.50 well spent. I got this AmazonBasics HDMI 2.0 Cable.

Success! The display now runs in UHD mode at 60 Hz. So apparently there was an issue with both my first cable (it actually may not have been an HDMI 2.0 cable anyways), and then the fancy cable from Monoprice.

 

[Suzuki@1473780084@1473780163]

Did you check the pixel clock (assuming no?). It's possible it was cheap crap, or the specs were for HDMI 1.4, because 1.4 and 2.0 use different chips inside the cable. Glad you got it working, thanks for the update!

 

[patterrr]

I don't know how to check the pixel clock, but am happy to do so if you can give me a pointer. I looked it up and my first cable was indeed an HDMI 1.4, which explains the issue. Still haven't resolved why the second cable (which is spec'd as HDMI 2.0 didn't work, but will follow up if I ever figure it out).

Thanks again for your help, I appreciated knowing I was on the right track with everything else before replacing the cable.

 

[Suzuki@1473780084@1473780163]

I'm sorry for not asking such an obvious question in the first place. But judging by your original description, it sounded like the cable and TV both meet spec. Anyways, go enjoy some 4k 60 goodness!