Unstable HDMI signal - Printable Version

Unstable HDMI signal - Printable Version

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Unstable HDMI signal - MichaelRu - 13th Apr, 2017 09:38 PM

Software
XBian version: 1.0
XBMC/Kodi version: 17.1
Overclock settings: Default

Hardware
Device type and model: Raspberry Pi 1, Model B 512 MB
Power supply rating: 1200mA
SD card size and make/type: 8GB
Network (Ethernet or wireless): Ethernet
Connected devices (TV, USB, network storage, ...): None

Log files
Link to logfile(s): http://paste.ubuntu.com/24372971/

Problem description:
I just installed XBian on my Raspberry Pi. When I connect it to the receiver in my home cinema then the beamer switches off every few seconds while I'm in the Kodi UI. A few seconds later, it comes back on. The display of the receiver flickers as if it doesn't recognize the signal from the cable.

When I connect the Pi to a normal monitor (with the same cable), then everything works.

I already added hdmi_safe=1 and config_hdmi_boost=7 to the config, but that didn't change anything. hdmi_safe changed the initial resolution to 480p but as soon as Kodi is started up, it switches to 1080p and has the same problem again. There are no messages in the log file when the signal is lost/comes back.
It seems like those problems only occur, when the Kodi UI is already started. Everything was ok during the installation routine from XBian and I also never see problems while the system boots before Kodi is up and running.

I had Kodi 16.0 (I think with OpenElec, but I'm not sure) on the same Pi connected through the same cables to the same receiver before and that worked. Now I wiped the SD card to install the newest version and the UI is unusable.

I also tried OpenElec 8.0.0 and 7.0.1, LibreElec 8.0.0 and 7.0.0 and OSMC, but they all have the same problem. That sounds like it is a problem between the Pi and the receiver, but it worked with the old version and it still works before Kodi is loaded up.

How to reproduce:
Just boot up and wait. After a maximum of 30secs the screen will get black.

RE: Unstable HDMI signal - Nachteule - 13th Apr, 2017 10:24 PM

HDMI cable already changed?

RE: Unstable HDMI signal - rikardo1979 - 13th Apr, 2017 11:53 PM

force the resolution of your TV in config file by adding appropriate lines coresponding to right resolution.

RE: Unstable HDMI signal - MichaelRu - 18th Apr, 2017 06:21 PM

Thanks for your tips!

I made some more tests.
The same HDMI cable works between Pi and monitor.
I tried a different HDMI cable to the AVR with the same results.

With 720p in the Kodi GUI the problem comes later, but it does arise nonetheless.

I also switched input connections on the AVR. The Bluray player works everywhere, the Pi nowhere. When I connect the Pi directly to the beamer, then the display works, but I'm missing the sound of course. So it seems to be a problem specifically between the Raspberry Pi and my Yamaha RX-V475.

RE: Unstable HDMI signal - Nachteule - 18th Apr, 2017 11:16 PM

@MichaelRu

Are you using CEC? If yes, you could deactivate it for testing

Another culprit could be the raspberry pi firmware. Unfortunately this is closed source, so we do not know what's going on inside firmware.

RE: Unstable HDMI signal - MichaelRu - 20th Apr, 2017 05:10 PM

I didn't configure CEC and don't need it. Is it on per default? Where can I disable it?

I also used NOOBS to install Raspbian. During the installation when NOOBS was running, I did see the problem too, but when Raspbian was started, everything was ok.
Unfortunately in Raspbian I didn't see what display settings it used in detail. It just used "Monitor defaults".
In Kodi I tried 1080p with 24, 30 and 60fps and 720p with 50fps. But they all showed the problem.

I could open an issue for the Raspberry firmware, but how can it be the firmware when Raspbian works (at least for those ~15mins I tried)?

RE: Unstable HDMI signal - rikardo1979 - 20th Apr, 2017 07:20 PM

Try some other device (BluRay player,DVD,etc) with same HDMI cable to same HDMI input on your projector if is going to be OK

Sent from my ONE A2003 using Tapatalk

RE: Unstable HDMI signal - Nachteule - 21st Apr, 2017 12:10 AM

(20th Apr, 2017 05:10 PM)MichaelRu Wrote: I didn't configure CEC and don't need it. Is it on per default? Where can I disable it?

Uncheck Kodi -> Settings -> System settings -> Input -> Peripherals -> CEC Adapter -> Enabled -> Ok

Quote:I also used NOOBS to install Raspbian. During the installation when NOOBS was running, I did see the problem too, but when Raspbian was started, everything was ok.
Unfortunately in Raspbian I didn't see what display settings it used in detail. It just used "Monitor defaults".
In Kodi I tried 1080p with 24, 30 and 60fps and 720p with 50fps. But they all showed the problem.

I could open an issue for the Raspberry firmware, but how can it be the firmware when Raspbian works (at least for those ~15mins I tried)?

How long are your HDMI cables? I have simililar issue between Hummingboard and TV (about one black screen for 3s per hour), however I have critical environment with 15m CEC cable but that does not bother me.

Maybe you could change HDMI setting on your AVR or Beamer, you have to play with them

RE: Unstable HDMI signal - deHakkelaar - 21st Apr, 2017 04:17 AM

(20th Apr, 2017 05:10 PM)MichaelRu Wrote: Unfortunately in Raspbian I didn't see what display settings it used in detail. It just used "Monitor defaults".
In Kodi I tried 1080p with 24, 30 and 60fps and 720p with 50fps. But they all showed the problem.

If you want to see current resolution displayed and some other useful info, below tool might be useful:

Terminal

$ tvservice -s
state 0x12000a [HDMI DMT (9) RGB full 4:3], 800x600 @ 60.00Hz, progressive

To see available resolutions:

Code:

tvservice -m DMT

and

Code:

tvservice -m CEA

You could also try to set a fixed resolution, instead of auto detecting, for XBian, AVR and beamer (all 3) so no cropping or other processing occurs.
Try to figure out the native resolution + framerate (Hz or fps) for the beamer and set fixed resolution for all devices accordingly.

RE: Unstable HDMI signal - MichaelRu - 8th May, 2017 05:56 PM

I swapped cables and connections at the receiver, disabled CEC, tried various configurations in config.txt, but nothing worked. Things I set in config.txt seem to only be used until the Kodi UI is started. Even on Raspbian I did get the problems I mentioned, but not as fast as in Kodi. I needed to wait about 15mins. The worst was LibreElec where the HDMI signal was lost every few seconds.

I played with it for days but eventually gave up. Now I bought a Fire TV, connected that with the same cable to the same input connection on the receiver and it works like a charm.

Thanks for your help nevertheless.

RE: Unstable HDMI signal - Skywatch - 8th May, 2017 07:57 PM

Try a better quality power supply on the pi - I suggest at least 2A.