[SOLVED] [S905x | 8.0.1e) Screen flickering/turning black for a moment - Nexbox A95x

nokodemus · April 10, 2017 at 11:44 AM

SOLVED (at least for me) - Solution
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Hi guys

First of all i'd like to thank kszaq and everybody else involved in LibreElec Amlogic Builds.
I've been usually using RPi2 and RPi3, but those builds encouraged me to get an AMLogic Device and try it out
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The issue, i have seems to be pretty common. I found youtube Videos, showing exactly the same issue and also some threads on some forums.
But there weren't any solutions. The only "hint" i found, was that this was a AMLogic Driver issue which they could or should resolve, just AMlogic an no one else would be able to. But anyway i'd like to try it here with an issue report

The flickering appears not just on LiveTV, also content e.g. from media libraries of different TV Channels around here is producing the issue.
Files from local network or external drives haven't been tested so far.
It also doesn't matter, if Wifi or Ethernet connected and doesn't matter if i use TVHeadend HTSP Client oder IPTV Simple to watch the content of my official (paid and not pirated) IPTV provider here in Austria (A1TV).
Another important thing is that i believe the flickering especially appears during fast scenes and / or scenes with a lot of movement.
I'm not sure if this is relevant but i think during quite static scenes playback is always and 100% fine.

The same content, LiveTV and media libraries are playing fine on Raspi2 and Raspi3 running LibreEelec 8.0.1 and connected to the same TV.
I also already tried different HDMI cables and Ports without success.

I'm not sure at the moment what else important i could tell you, so I'll directly go on with my specs, a Video of the issue and the log:

Hardware: Nexbox A95x (S905x) connected by HDMI
TV: LG 55LM620s (2012 model)
Build: Libreelec S905x 8.0.1e (2017-04-08) booted from SD
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Video:

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Flickering appears at 1:09 and 2:16 during a Live-TV Channel (TVHeadend HTSP Client)
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Debug Log: Zippyshare.com -

Log got pretty big, because i had to wait for the flickering to appear. The flickering moment should have happened between 11:50 and 11:51.

Thank you very much for all your efforts on those AMLogic Builds for Libreelec. Probably there's also a solution even for this issue.
Thanks in advance and greetings from Austria

clarkss12 · April 10, 2017 at 6:05 PM

That appears to be a loss of signal. Since you tried different HDMI cables and HDMI ports, you can try the settings/player/video and set the "Adjust display refresh rate" to "off", and see if that helps.

erpalma · April 10, 2017 at 9:30 PM

Nope, that happens on my box too with versions 8.0.1d and 8.0.1e. All fine with 8.0.1c

nokodemus · April 11, 2017 at 8:28 AM

Quote from clarkss12

That appears to be a loss of signal. Since you tried different HDMI cables and HDMI ports, you can try the settings/player/video and set the "Adjust display refresh rate" to "off", and see if that helps.

Thanks for that hint. Unfortunately deactivating the refresh rate adjustment didn't have any consequences. Same as before ...

Quote from erpalma

Nope, that happens on my box too with versions 8.0.1d and 8.0.1e. All fine with 8.0.1c

Really?
I'm not sure on which build i started, but i'll definitely check a fresh <= 8.0.1c install. Thank you.

Meanwhile i also had another theory about the issue.
According to Libreelec Systeminfo, as well as CPU-Z within android and SSH "cputemp" the SoC is heating up to about 80°C (Estuary, idle)
After just about 5 minutes of load (e.g. Kodi Backup procedure) it's even heating up to about 90°C.

Does this sound "normal" ?

Once again thank you guys for your hints

clarkss12 · April 11, 2017 at 1:28 PM

For whatever reason, my screen started to blackout also. I reverted back to 8.0.1c, and all is well now. So, guess there is a video handshake problem with the later versions of 8.0.1. Did not test the over heating theory.

gatmalrex · April 11, 2017 at 5:42 PM

Quote from clarkss12

For whatever reason, my screen started to blackout also. I reverted back to 8.0.1c, and all is well now. So, guess there is a video handshake problem with the later versions of 8.0.1. Did not test the over heating theory.

I can confirm that I'm also having this issue 8.0.1d onwards. Some videos appear as a black screen. Pressing the 'back' button on the remote goes back to the folder.

Edit: using a new HDMI cable with a 2160p @ 60hz TV

**mmpp** · April 11, 2017 at 6:14 PM

As a short-term workaround, please try to force the hdmi output to the RGB colorspace. I use both S905 and S905X with the latest dev version and did not see any problems with the picture. See thread-1129.html for reference.

nokodemus · April 12, 2017 at 6:09 AM

A combination of both first hints did it for me. Thank you guys.
Deactivating display refresh rate adjustment didn't resolve the problem on Build 8.0.1e.
Build 8.0.1c with activated adjustment (on start/stop) also produced the flickering.

But 8.0.1c combined with completely deactivated refresh rate adjustment seems to resolve it, at least so far.
Unfortunately i'd like to watch content in the refresh rate, it's intended to being watched. Without that setting that won't be possible, right?

Quote from mmpp

As a short-term workaround, please try to force the hdmi output to the RGB colorspace. I use both S905 and S905X with the latest dev version and did not see any problems with the picture. See thread-1129.html for reference.

Thank you

As far as i can see i can force RGB using config.txt on a RasPi ... But how to force it on an AMLogic Device ...
Or did i just miss the right place in the thread?

Or should i just try latest dev build too ...

dimitrij2k · April 12, 2017 at 6:18 AM

Same flickering here

**mmpp** · April 12, 2017 at 8:02 AM

The command for forceRGB is

Code

echo 1 > /sys/class/amhdmitx/amhdmitx0/output_rgb

You can type it using SSH while your box is on. If the workaround works fine, you can add it to autostart.sh.

nokodemus · April 16, 2017 at 8:41 AM

Quote from mmpp
The command for forceRGB is
Code
echo 1 > /sys/class/amhdmitx/amhdmitx0/output_rgb
You can type it using SSH while your box is on. If the workaround works fine, you can add it to autostart.sh.

First of all sry for being a little late with feedback.

Thank you very much for the hint. I sent the command to the box using putty, which resulted in a short flickering. So it should have worked, right?
But unfortunately the mentioned flickering issue also wasn't resolved by this procedure ...

Besides this the box also keeps getting hotter and hotter, inbetween 80-85C in idle and about 95C and even higher SoC temperature after a short little load.
So i decided to return the box. Next try will be a Mini M8S II.

Thank you all for your efforts and hints regarding this issue. I'll keep you updated, if the issue also appears on the new Mini M8S II
Greets from Austria and happy easter and nice holidays to all of you

gamicoulas · April 19, 2017 at 7:09 PM

Quote from mmpp
The command for forceRGB is
Code
echo 1 > /sys/class/amhdmitx/amhdmitx0/output_rgb
You can type it using SSH while your box is on. If the workaround works fine, you can add it to autostart.sh.

On my box with a 10 year old Sharp Aquos TV it seems to do the trick as long as I reset it back to 0, as with 1 I get no output.

To be clear, my TV will flicker randomly by a refresh rate change. Sometimes it does sometimes it doesn't. So by issuing

Code

echo 1 > /sys/class/amhdmitx/amhdmitx0/output_rgb

I lose output, so immediately I revert it by

Code

echo 0 > /sys/class/amhdmitx/amhdmitx0/output_rgb

and then I get a stable screen until a later unlucky refresh rate change. Now I noticed that the flickering might come back if I switch off and on the TV. The longer it stays switched off the more likely is to flicker on the next power up. FYI this issue has cropped up sometime around the early 8.0.1 updates. It practically makes auto refresh rate switching unsuitable for these builds...

nokodemus · May 21, 2017 at 9:32 AM

Hi guys

I don't know why and can't really explain how, but after 3-4 Days without any issue and some hours of playback without issues i think i can safely say, that the issue is resolved, at least for me.

Luckily recently i bought a new TV-Rack. Therefore all the cable connections had to be freshly connected.
After that after a while i realized that the flickering didn't appear any more. I wanted to know why.
As i had the issue before on every single Build from 8.01c - 8.01k, the only thing which made sense, was some Cable connection, probably HDMI.
I was pretty sure, i already had tested different cables and Ports long ago and couldn't resolve the problem this way ...
but probably this was a wrong conclusion?

So i tested all the HDMI ports with 2 different cables, once again, with following result:
HDMI 1,2,4 are working fine so far. ONLY HDMI 3 is producing the issue.
It also doesn't matter, if i activate or deactivate automatic display refresh rate adjustment. Everything is fine on HDMi 1,2,4.
I'm especially saying that, because deactivating refresh rate adjustment resolves the issue also on HDMI3
I don't have a clue why ...
It also doesn't matter if RGB or YUV Output --> all fine

HDMI Port 3 is also set up with identical picture and audio settings, as e.g. HDMI 2. Therefore i think i can eliminate potentially wrong TV-Settings.

Another interesting fact is that HDMI 3 only produces the issue in combination with Mini M8S II and Libreelec (or Android, doesn't matter)
My Raspberry Pi 2 with Libreelec (which meanwhile is connected to HDMI3) is running absolutely fine, as ever.

That's weird, isn't it? Does anybody have any thoughts about this ( at least to me ) very strange behavior?

Probably someone else will also able to resolve the issue like that. I hope so ...

Greets from Austria

edragon · May 24, 2017 at 3:19 AM

Quote from nokodemus

Hi guys

I don't know why and can't really explain how, but after 3-4 Days without any issue and some hours of playback without issues i think i can safely say, that the issue is resolved, at least for me.

Luckily recently i bought a new TV-Rack. Therefore all the cable connections had to be freshly connected.
After that after a while i realized that the flickering didn't appear any more. I wanted to know why.
As i had the issue before on every single Build from 8.01c - 8.01k, the only thing which made sense, was some Cable connection, probably HDMI.
I was pretty sure, i already had tested different cables and Ports long ago and couldn't resolve the problem this way ...
but probably this was a wrong conclusion?

So i tested all the HDMI ports with 2 different cables, once again, with following result:
HDMI 1,2,4 are working fine so far. ONLY HDMI 3 is producing the issue.
It also doesn't matter, if i activate or deactivate automatic display refresh rate adjustment. Everything is fine on HDMi 1,2,4.
I'm especially saying that, because deactivating refresh rate adjustment resolves the issue also on HDMI3
I don't have a clue why ...
It also doesn't matter if RGB or YUV Output --> all fine

HDMI Port 3 is also set up with identical picture and audio settings, as e.g. HDMI 2. Therefore i think i can eliminate potentially wrong TV-Settings.

Another interesting fact is that HDMI 3 only produces the issue in combination with Mini M8S II and Libreelec (or Android, doesn't matter)
My Raspberry Pi 2 with Libreelec (which meanwhile is connected to HDMI3) is running absolutely fine, as ever.

That's weird, isn't it? Does anybody have any thoughts about this ( at least to me ) very strange behavior?

Probably someone else will also able to resolve the issue like that. I hope so ...

Greets from Austria

Display More

Could be the power of HDMI-3 is insufficient for Mini M8S II but enough power for Raspberry Pi 2.

panterck · May 24, 2017 at 10:03 AM

I have the same issues. I use Minix U1 on Samsung 4kTV and another U1 on Sony 4kTV. The problem is present and mostly

on Samsung (it flickers randomly..sometimes 20times per 40min episode, sometimes it's ok, sometimes it flickers when I'm

in the menu), on Sony TV I saw this problem occur 2 times in past few months.

Anyway...the problem goes away on Samsung when I downgrade to LE7. I tried all HDMI ports and it's the same on every one of them.