THX1182
Posts: 22
Joined: Fri Oct 11, 2019 6:24 pm

Re: Trouble Getting HDMI Output From RPi4

Tue Nov 05, 2019 7:51 pm

THX1182 wrote:
Tue Oct 29, 2019 8:23 pm
I've been having issues with hdmi as well, basically tried everything I could find, but nothing seems to resolve the issue...

(Swapping cables, config.txt editing, reinstalling, new Power supply)

The Pi loses connection with my TV for two seconds, after playing media of any kind... I think it's hdmi audio related, because it does not happen with analogue audio.

Here's a video of what's happening:

https://imgur.com/gallery/n2bRnWE

These are some of the outputs of tvservice:

1 attached device(s), display ID's are :
Display Number 2, type HDMI 0

HDMI events what happens after media is played:

Starting to monitor for HDMI events

HDMI cable is unplugged. Display 2
HDMI is attached
HDMI cable is unplugged. Display 2
HDMI is attached

state 0xa [HDMI CUSTOM RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive

Audio information:

PCM supported: Max channels: 2, Max samplerate: 48kHz, Max samplesize 16 bits.
AC3 supported: Max channels: 6, Max samplerate: 48kHz, Max rate 640 kb/s.
DTS supported: Max channels: 2, Max samplerate: 48kHz, Max rate 640 kb/s.


Not to hijack this thread but since the raspi team is looking into "hdmi problems", i decided to link my thread here before my thread dies.

Here's a link to my original thread:

https://www.raspberrypi.org/forums/view ... 5#p1558785

Hope that my issue falls under the "hdmi issues", that the developers are looking at, because this has been driving me crazy for weeks now.
Well i ended up buying a usb audio adapter, and a good rca cable to "fix" my issue... It's completely bonkers when you think of it, every hdmi machine I have functions normally with my tv... (Sharp Aquos).

I understand the Pi team have thousands of issues to fix, but a simple sorry we can't resolve your issue would have been nice.

Anyways keep up the great work!

dominic03
Posts: 91
Joined: Fri Dec 21, 2018 1:50 am

Re: Trouble Getting HDMI Output From RPi4

Thu Dec 26, 2019 9:38 pm

My Raspberry Pi 4 that I got yesterday has no output from HDMI 0 when using PINN, unless I leave it unplugged and plug it in after the Pi starts up. Then I get very low resolution video, with messed up colors. Note that if it is plugged in while booting, HDMI 0 gives a black screen while HDMI 1 gives 'No Signal'.
Image
I checked the HDMI cable with another HDMI 1080p device, and it works perfectly fine on it.
Any suggestions on what to try?

By the way, HDMI 1 works just fine, but is not compatible with PINN.

Edit: I got the output to work, I don't know how, but I get weird corruption/ interference. I tried adjusting hdmi_boost but it doesn't help.
Edit 2: Working fine with the cable in a certain position, guess it is a cable problem. Never buy cheap HDMI cables!
Raspberry Pi 4B running Raspbian Buster v3.1 (via PINN)
Kingston 32 GB C10 (U1) microSD
Sceptre E225W 22" 75hz 1080p monitor
Flash drive for backups and swap
-or-
pi-top 3 running Raspbian with drivers and pi-topHUB 2.0 / 16GB SanDisk C10 microSD

User avatar
procount
Posts: 2051
Joined: Thu Jun 27, 2013 12:32 pm
Location: UK

Re: Trouble Getting HDMI Output From RPi4

Fri Dec 27, 2019 12:16 am

If your HDMI cable connections are flaky, the RPi is probably not reading the monitor EDID information reliably.
In this case you can force a particular resolution by adding the following to config.txt on the PINN partition (create it if it doesn't exist):

Code: Select all

hdmi_ignore_edid=0xa5000080

hdmi_group=2
hdmi_mode=28	
Change the hdmi_group and hdmi_modes to suit your monitor.
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

dominic03
Posts: 91
Joined: Fri Dec 21, 2018 1:50 am

Re: Trouble Getting HDMI Output From RPi4

Fri Dec 27, 2019 12:25 am

procount wrote:
Fri Dec 27, 2019 12:16 am
If your HDMI cable connections are flaky, the RPi is probably not reading the monitor EDID information reliably.
In this case you can force a particular resolution by adding the following to config.txt on the PINN partition (create it if it doesn't exist):

Code: Select all

hdmi_ignore_edid=0xa5000080

hdmi_group=2
hdmi_mode=28	
Change the hdmi_group and hdmi_modes to suit your monitor.
Can I use custom CVT modes?
Raspberry Pi 4B running Raspbian Buster v3.1 (via PINN)
Kingston 32 GB C10 (U1) microSD
Sceptre E225W 22" 75hz 1080p monitor
Flash drive for backups and swap
-or-
pi-top 3 running Raspbian with drivers and pi-topHUB 2.0 / 16GB SanDisk C10 microSD

User avatar
procount
Posts: 2051
Joined: Thu Jun 27, 2013 12:32 pm
Location: UK

Re: Trouble Getting HDMI Output From RPi4

Fri Dec 27, 2019 12:33 am

Of course.
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

Lenten
Posts: 1
Joined: Wed Feb 05, 2020 10:00 am

Re: Trouble Getting HDMI Output From RPi4

Wed Feb 05, 2020 10:16 am

I'm getting really desperate …
I tried clean BUSTER image and clean NOOBS and a working sdcard from my Pi3B+ …
My SHARP tv blacks out … No compatible signal.

After trying all the tips ( so many posts with hdmi_safemode, booster, ignore…) I found a version of config.txt where I got a blurred image and managed to enable VNC & SSH.
I tried tvservice & found out hdmi_group=1 & hdmi_mode=31 was native to my TV, changed config.txt
Now when it boots I see the raspberries perfectly, and for a second the BUSTER desktop gives me hope...
Then the TV switches mode again, apparently to 1024x768 blacks out and 'No compatible signal' appears on te TV again.

I'm about ready to give up ...

jvalenti370
Posts: 1
Joined: Sun Feb 09, 2020 11:15 pm

Re: Trouble Getting HDMI Output From RPi4

Sun Feb 09, 2020 11:23 pm

procount wrote:
Fri Dec 27, 2019 12:16 am
If your HDMI cable connections are flaky, the RPi is probably not reading the monitor EDID information reliably.
In this case you can force a particular resolution by adding the following to config.txt on the PINN partition (create it if it doesn't exist):

Code: Select all

hdmi_ignore_edid=0xa5000080

hdmi_group=2
hdmi_mode=28	
Change the hdmi_group and hdmi_modes to suit your monitor.
Thank you for this advice. I have had a LOT of trouble getting video out via HDMI0. Just to install an operation system I had to first configure safemode in the Config.txt file. The problem did not end there because once I then updated Ubuntu and then removed safemode, I was getting a black screen. I am delighted I stumbled upon your suggestion. I manually edited the config.txt from a Windows computer, booted again and now I have a sensible resolution that actually works.

One oddity remains! When I power up my Raspberry Pi 4, I must remove and then reinsert my HDMI cable into HMDI-0. Only then will it actually boot. Any ideas how to fix that accidentally-discovered work-around?

Thanks again!

User avatar
Mortimer
Posts: 925
Joined: Sun Jun 10, 2012 3:57 pm

Re: Trouble Getting HDMI Output From RPi4

Sat Mar 28, 2020 10:54 pm

Well now that I am stuck at home, for obvious reasons, I thought I would have another crack at getting this RPi4 working with my Motorola Atrix lapdock.

It's working!!

It was adding the hdmi_ignore_edid line that done it! Although I cannot get it to be the exact native resolution. I put the following into "config.txt":

Code: Select all

framebuffer_width=1366
framebuffer_height=768
hdmi_force_hotplug=1
hdmi_ignore_edid=0xa5000080
hdmi_group=2
hdmi_mode=86
But the lapdock screen is being driven at [email protected] which is mode 39 not the mode 86 I was after, but 6 pixels lost across the width isn't bad.

I had been getting the RPi4 basically up and running using a 24" 1920x1200 Dell monitor I have borrowed from work. Surprisingly the RPi booted into this mode on the lapdock, and it was actually legible. I didn't think the lapdock would be able to scale such a high resolution but it does!
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