I just replaced my old MSI HTPC unit with NUC and found a strange "problem" reproduced on 1 TV and 3 HDMI monitors.
First of all, boot logo looks corrupted,
some text and graphics in BIOS as well. If mouse is over those "missing" pixels and areas, they are "restored" while mouse is there.
Screenshot taken by internal utility does not show those anomalies
I've updated BIOS to most recent version, cleared CMOS, checked memory. But, when system boots up (Ubuntu 18.04, as kernel in 16.04 does not support this NUC) to FullHD, everything looks fine, no problems at all.
With the exception of the GRUB menu (text is missing pixels too)
and my TV thinks that NUC is disconnected during bootup, only reinsertion of HDMI cable helps to get image back. I know that Linux is not supported (while BIOS has UEFI option for it), but the problem is not related to OS as it happens even in BIOS. It looks like there is a problem with upscale or conversion from 4:3 (internal utility's screenshot is close to it) to 16:9 ratio. So, should I replace NUC or is that an expected behaviour?
I can't say anything about the screen corruption, but I do have some info regarding the loss of HDMI signal during boot:
I and several others are experiencing this issue. There seems to be an issue with Gemini Lake and Linux, where the HDMI signal is lost after loading the i915 Linux display driver. It seems to also manifest itself during other mode changes, for example when simply switching resolution and refresh rates. As you say, the display can be restored by pulling and reinsering the HDMI cable. It also works to simply restart the TV.
Here's an issue report on the official i915 bug tracker: https://bugs.freedesktop.org/show_bug.cgi?id=105887 https://bugs.freedesktop.org/show_bug.cgi?id=105887
Also, check the comments on the link below, where a few others report the same issue: http://nucblog.net/2018/04/first-major-bios-update-for-nuc7cjyh-gemini-lake-nuc/# comment-6259 First Major BIOS Update for NUC7CJYH (Gemini Lake NUC) – The NUC Blog
It seems HDMI on Gemini Lake is not ready for prime time, at least not on Linux. Damn shame this wasn't worked out before release.
Yes, thank you. The problem with i915 is exactly the same as described by the link (and NUC works normally during boot with the regular monitor).
But nobody else mentions problems with corrupted logo and fonts, so I should probably change device while the replacement window is still open.
ps: I also have a wild guess (which may be technically incorrect, but I did not dig so deep yet):
Pixels-areas problems arise when TV/monitor does not understand what color to use. When cursor's shadow is over that area, it is changing the background color to darker one and TV/monitor is able to show it.
It is like clipping of the analog signal (just an analogy). This NUC has HDMI 2.0a native support, so may be it sends extra bits, which are not recognized normally by the older panel. I need to find 4k monitor or TV to check it.
Our June Canyon NUCs will not support HDR due to the CPU installed on them:
Intel® NUC Kit NUC7CJYH : Intel® Celeron® Processor J4005 (Intel® UHD Graphics 600)
Intel® NUC Kit NUC7PJYH : Intel® Pentium® Silver Processor J5005 (Intel® UHD Graphics 605)
These units come with embedded graphics that do not support HDR since it is a feature that is currently supported just with Core processors
Have you tried different RAM? Since the GPU on the SoC uses system memory for its screen buffer, could be one or more of your DIMMs are bad. JY only supports 2133 or 2400 MHz DIMMs, 8GB max for both slots.
I see the same issue with losing signal through HDMI on an old 1080p Samsung TV. Could it be something with the graphics driver built into the latest Ubuntu 18.04? I don't seem to have any issues when going through POST, seeing the splash screen or entering Visual BIOS, or in Windows 10 RS4 (1803). Only when I start to enter the desktop in Ubuntu.
I have tested RAM with Memtest86+. Also, internal screenshot utility gives a normal screen, as well as completely booted OS (tested it under different loads and benchmarks).
That is why I narrowed it to the HDMI connection.
Strange that it seems to be only on TVs and not monitors. Just for completeness sake, have you tried different RAM modules? I'm not seeing the screen corruption on my system using Crucial 4GB 2400MHz SO-DIMM. Could be you got a bad unit. Might want to RMA that and try another one. Intel is great about supporting their 3 year warranty.
Corrupted logo and bios text are visible on all 4 devices, TV's problem happens only during Linux bootup (monitors are normally waiting for the image). My memory is Patriot 4GB 2400, no problems with it (and I do not have a spare module right now). But you are right, it is easier just to replace unit with Newegg. Weird logo and text do not bother me a lot, I just do not want it to be a sign of some other, more serious, problem.
Have you tried a different HDMI cable? When you see the same issues on all 4 devices, are you using the same cable on all of them? I've been playing with my JY NUC on an old 1080p monitor using Ubuntu 18.04 for about an hour now and haven't seen any issues. I even did a software update to Ubuntu and didn't see any change.
3 different HDMI cables (6ft, 3ft and 15ft). Cable can not affect only some pixels in persistent locations on the screen. And, as I wrote before, there are no problems in Ubuntu 18.04 with text, graphics, video or anything else (and I had a lot of them in 16.04).
Multi-monitor driver support is a damn joke as of currently, both in Windows and in Linux.
I've a setup (a modern 4K monitor, and an older 1080p one) that outright refuses to work, and I've only managed to activate the 4K one. No matter what I try, the 1080p one refuses to show anything but a black screen (except when booting or in the BIOS, or with default generic Windows drivers....both monitors work correctly in those cases). Heck, even if I disable via BIOS the HDMI port of the 4K monitor in order to force the output to go to the 1080p one, it only works right until Windows loads up, then the output IGNORES the BIOS command and jumps to the 4K monitor. Just incredible.
And no, like I said it's not hardware-related at all. It's the ridiculous drivers we have.
My JY seems to be working perfectly.
I have a Samsung 40" TV on HDMI1 running 4K@60Hz and a Seiki 24" TV on HDMI2 running 1080p@60Hz. Both TVs working as expected in both BIOS and Windows (I am not set up to run Linux, so no results there).
BIOS installed is the latest (37). Graphics driver installed is latest (4944). O/S is Windows 10 Pro 1804 with all available updates installed.
Any configuration tip then? Cos I absolutely don't know what else to do. None of the driver multimonitor settings do the trick, neither lowering the resolution manually to 1080p, even in the 4K monitor.
Well, apart from formatting, force the primary HDMI to the 1080p monitor, and reinstall Windows. But that'd only swap the problem from one monitor to the other.
Sorry, nothing to suggest. The BIOS configuration is at defaults. I installed release 1703 originally, downloading and installing all of the latest drivers available on the NUC's downloads page. I then manually did the upgrade to 1804. In this upgrade, the only issue I ran into was a loss of HDMI audio. I reinstalled the 4944 graphics package and it fixed that issue.
I would note that I did all this with only the 4K monitor connected. The addition of the second monitor was to look at your issue. Perhaps that is what you need to do; install Windows with only the 4K monitor connected and then, once everything is installed and updated, connect the other monitor...
Hope this helps,
Replacement unit arrived today, it does not have defects mentioned in my original post (I did not try to boot it up in Linux while connected to TV, yet, but I think it can be solved by the script at startup).
Thank you all.
ps: I am starting to hate NUC - in a new unit I can not disable UEFI boot. Secure boot is disabled, even cleared boot data, but "UEFI boot" checkbox is checked and grayed out. I have an old customized Ubuntu setup, upgraded to recent version. That is why I need non-UEFI boot and was able to do it on the defective unit, but not here.
It's good to hear that you have a good experience with Samsung 40" TV on HDMI1 running 4K@60Hz. I'm not as lucky, my NUC7PJYH seems to be incompatible with all 4 Samsung devices I tried (one 4K monitor and three 4K TVs).
Could you please give more details regarding your setup:
Answers to your questions:
Conclusion? The NUC certainly does not like UHD being enabled in this Samsung TV.