AssembledAdam
Posts: 3
Joined: Mon Mar 02, 2020 7:57 pm

Pi 4 Model B. No output on LG TV. Tried everything.

Mon Mar 02, 2020 8:30 pm

Hello. Pi 4 with Raspbian 10 boots fine with an ordinary Acer IPS monitor via HDMI.

But it doesn't work with an LG 55LF580V (there is no output at all). I've been trying for approximately 4 hours.

Setup:
- HDMI is plugged in via port 0 on the Pi
- The select input source is correct
- The TV is on with the 'No signal' animation.
- The Pi detects the TV, see below.

Code: Select all

pi@raspberrypi:~ $ tvservice -l
1 attached device(s), display ID's are : 
Display Number 2, type HDMI 0
pi@raspberrypi:~ $ tvservice -n
device_name=GSM-LG_TV
- Detected modes:

Code: Select all

pi@raspberrypi:~ $ tvservice -m "CEA"
Group CEA has 15 modes:
           mode 1: 640x480 @ 60Hz 4:3, clock:25MHz progressive 
           mode 2: 720x480 @ 60Hz 4:3, clock:27MHz progressive 
           mode 3: 720x480 @ 60Hz 16:9, clock:27MHz progressive 
           mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz progressive 
           mode 5: 1920x1080 @ 60Hz 16:9, clock:74MHz interlaced 
  (prefer) mode 16: 1920x1080 @ 60Hz 16:9, clock:148MHz progressive 
           mode 17: 720x576 @ 50Hz 4:3, clock:27MHz progressive 
           mode 18: 720x576 @ 50Hz 16:9, clock:27MHz progressive 
           mode 19: 1280x720 @ 50Hz 16:9, clock:74MHz progressive 
           mode 20: 1920x1080 @ 50Hz 16:9, clock:74MHz interlaced 
           mode 21: 720x576 @ 50Hz 4:3, clock:27MHz x2 interlaced 
  (native) mode 31: 1920x1080 @ 50Hz 16:9, clock:148MHz progressive 
           mode 32: 1920x1080 @ 24Hz 16:9, clock:74MHz progressive 
           mode 33: 1920x1080 @ 25Hz 16:9, clock:74MHz progressive 
           mode 34: 1920x1080 @ 30Hz 16:9, clock:74MHz progressive 
pi@raspberrypi:~ $ tvservice -m "DMT"
Group DMT has 5 modes:
           mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive 
           mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive 
           mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive 
           mode 35: 1280x1024 @ 60Hz 5:4, clock:108MHz progressive 
           mode 39: 1360x768 @ 60Hz 16:9, clock:85MHz progressive 
I've tried:
- Trying a different HDMI port on the TV
- Switching the HDMI cable over
- Updating the TV's firmware
- Plugging my laptop into the TV with the same cable/port and that works, so this rules out the cable, port, and TV.
- hdmi_safe=1
- config_hdmi_boost=(4, 7, and 11)
- Dumping the EDID file (as edid.dat), setting hdmi_edid_file=1, and placing it in the /boot directory and rebooting
- Specifically setting the preferred mode via hdmi_group=1 and hdmi_mode=16
- hdmi_drive=2
- overscan=(1 and 0)

For every change I reboot the Pi.

Nothing has worked. Any ideas?

otherkirby
Posts: 2
Joined: Fri Mar 06, 2020 9:54 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Fri Mar 06, 2020 10:05 pm

Hey, sorry, I don't have a solution, because I am facing the exact same issue. Can I ask you how you accessed that code? I haven't tinkered with that and that might solve my problem. haha.

I did see something on the Pi website regarding if your SPI EEPROM is corrupted, to load that on the rasp pi. So maybe it's your SPI EEPROM?? I don't know

AssembledAdam
Posts: 3
Joined: Mon Mar 02, 2020 7:57 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Sat Mar 07, 2020 12:34 am

Anyone?

If someone gives me an answer that leads me to the solution I'll wire them £10.

Thanks

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DougieLawson
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Sat Mar 07, 2020 1:46 am

When did you build your SDCard?
Have you updated it with sudo apt update; sudo apt dist-upgrade -y; sudo reboot ?

Try building a new SDCard with Buster 2020-02-13 (you could use the new RPT SDCard imager tool to do that).
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AssembledAdam
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Joined: Mon Mar 02, 2020 7:57 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Sat Mar 07, 2020 1:55 am

SD card was made just a week ago using an image downloaded the same evening.

Thanks for the suggestion. I'll try that as soon as I'm next to the Pi again.

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kerry_s
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Sat Mar 07, 2020 2:00 am

https://www.raspberrypi.org/documentati ... t/video.md

try adding the:

Code: Select all

hdmi_group=2
hdmi_mode=82
to the bottom of /boot/config.txt

inspiral
Posts: 1
Joined: Mon Apr 13, 2020 9:02 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Mon Apr 13, 2020 9:39 pm

Did you solve this ? I have the same issue :-(

ctor
Posts: 2
Joined: Mon May 04, 2020 11:06 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Mon May 04, 2020 11:29 pm

Having the same problems...

LG TV model = 32LN570R

I have recently got a new raspberry pi 4 B (4gb), I tried it flashing the image of Buster Raspian following diffirent methods. Likewise, I have tried several modifications in confix.txt:

1) hdmi_safe=1
2) hdmi_force_hotplug=1
3) hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=4
4) hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=4
config_hdmi_boost = 4 (or 5, 7, 11)
5) hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=4
config_hdmi_boost = 7
hdmi_ignore_edid=0xa5000080

I am using the official Raspberry power supply (3A) and a Joy-It HDMI wire connected to the port 0 (close to the USB-C port of the power supply). It is OK. I have also tried it with the mouse/keybord USB disconnected. No other connections.

PWR LED is on and ACT LED is working properly. Headless is working properly with VNC.

I don't know what to do?

Thanks

ctor
Posts: 2
Joined: Mon May 04, 2020 11:06 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Tue May 05, 2020 9:25 pm

Now is working, but I dont know why...

Tired of trying and tryig I decided to run it headless. After that, now the HDMI is working properly. But I didnt make any particular modification to enable the HDMI.

I did an update from the Advanced Options in the Config Menu; but I was already running the last official version of Raspbian, downloaded from this site...

After that I run the RPi from the VNC. There, the only setting I modified about the video is the resolution and the 3d motor. However, I set the resolution that I wanted for my VNC Viewer, that is different than the resolution of the LG TV...

I dont know why, but now it is working. Try to update. Maybe you are lucky with this.

PhilBr
Posts: 85
Joined: Tue Oct 31, 2017 5:28 pm

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Tue May 05, 2020 10:22 pm

Is the order in which pi and TV are powered up relevant?
Had that problem with Ubuntu + amd a few years ago.
Phil

nenhumdenos
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Joined: Wed May 06, 2020 2:48 am

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Wed May 06, 2020 6:00 pm

I have the same issue on my RPi 4B 4GB. But it was a slow thing here. First my TV stopped working FullHD when the PI was there (I use Kodi on it), then the HDMI CEC went away, then it only would run at 1024x768 resolution. Then I tried on a new sdcard for a new LibreELEC install and it again booted to 1024 pixels. I then turned it off, and now I got no signal at all. Once on the other monitor it showed some thing, now I get nothing. 3 different screens ( two TV's, one monitor) and nothing.

Is there anything I can try on it?

thanks,

matheus

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kerry_s
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Wed May 06, 2020 6:54 pm

sounds like bad hdmi cables or you've broken your hdmi ports.

Tuedel
Posts: 11
Joined: Wed May 06, 2020 7:24 am

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Wed May 06, 2020 11:08 pm

Hej!

I had the same problem with an older Samsung TV. I could solve it by usinig SSH and disabling the GL-driver (sudo raspi-config, advanced settings). Maybe that helps ya.

Manos
Posts: 5
Joined: Thu Jan 23, 2020 3:22 am

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Thu May 07, 2020 12:05 am

I had the same problem with my Sony Bravia and have finally decided to give up after putting too much time and money into trying to solve the problem with the Pi 4. Video problems like this seem to be pretty common for the Pi 4 where they weren't for the Pi 3. Needless to say I'm seriously disappointed in the product and will look into other mini PCs in the future while I fall back to the Pi 3b.

nenhumdenos
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Thu May 07, 2020 12:01 pm

Tuedel wrote:
Wed May 06, 2020 11:08 pm
Hej!

I had the same problem with an older Samsung TV. I could solve it by usinig SSH and disabling the GL-driver (sudo raspi-config, advanced settings). Maybe that helps ya.
Hi,

as I have no OS ready to use on the board, I need something that would have ssh enabled by default and will boot to acquire IP using DHCP also by itself, so I can use it headless. Any hints?

I am a FreeBSD guy, but as for the RPi4 there is no FreeBSD stable support so far, I will be glad to hear linux suggestions. I tried LibreELEC, Manjaro, and Raspbian Lite and tcpdump on the RPi4 ethernet showed no signs of life form.

So far I second the Manos disappointment on the RPi4. Too bad ...

thanks,

phineyboy
Posts: 24
Joined: Sun Dec 21, 2014 1:54 am

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Thu May 07, 2020 5:15 pm

There is a Raspbian Buster image that has ssh and VNC enabled by default so you can bring it up headless. https://remote.it/downloads/#pi

You can use it to bring up any Pi (Zero, 3,4) in Headless mode. Not sure about Pi 1 and 2?

There is a video that explains it but it's kinda long. But the first few minutes show how the headless works. https://youtu.be/j9EsCvBF-cA

jamesh
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Thu May 07, 2020 8:41 pm

The HDMI output HW on the PI4 has changed a bit, as has the software, but on the whole it works fine for the vast majority (we've sold 2M or so, the number of reports on HDMI issues is miniscule in comparison), but there's obviously something weird going on for a tiny number of people/devices. However, we have never been able to replicate any of the reported issues in the office which does make it difficult to debug, when you cannot make it go wrong.

What resolution are these devices?
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Darren_L
Posts: 8
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Thu May 07, 2020 11:45 pm

Hello jamesh,

I've got a similar issue, no hdmi out with one monitor and another monitor working mostly ok (signal flickers off for a second or so about once a minute). I've got the official power supply, brand new Pi 4 Model 4 B 4G and new official hdmi cable. I think I've tried everything that has been mentioned in various posts on this forum and I've posted all the info here (hopefully I haven't missed anything obvious):

viewtopic.php?f=28&t=273020&p=1654810#p1654810

I would be able to diagnose the issue further if I had access to my office as I have another raspberry pi 4 model 4 B 4G there too . This is working fine with a dell monitor, so I'd be able to at least eliminate any hardware issues by testing various combinations.

I wondered if I could offer any help with debugging the issue? I've started looking at Raspbian and the pi firmware on github to see if any pull requests stand out as worth compiling locally, there are a few hdmi items pending but nothing that stands out as a fix for this issue.

I don't have any hardware diagnosis kit at home sadly like a digital storage scope that might helpful but if the issue can be investigated from a purely software point of view I'd be happy to help out. Either by debugging myself (more decades of experience than I care to mention in coding, a fair amount in C/C++ and device drivers) or giving you remote access via maybe OpenVPN to connect into a VNC or SSH session.

So far I've tried a few extra things like watching /opt/vc/bin/tvservice --monitor and switching resolution also using /opt/vc/bin/tvservice while connected to the problem monitor to see if anything is reported but nothing is.

I've also tried installing 64 bit Ubuntu 20.04 LTS (initially server then added Ubuntu Mate after) thinking a different linux variant/kernel might yield different results but the hdmi behaves exactly the same on both monitors. I was a bit surprised by this but I have no idea if any of the driver code is cross pollinated, or where the firmware/hardware on the different linux variants overlap.

sentineljones
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Joined: Fri May 08, 2020 5:50 am

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Fri May 08, 2020 6:58 am

jamesh wrote:
Thu May 07, 2020 8:41 pm
The HDMI output HW on the PI4 has changed a bit, as has the software, but on the whole it works fine for the vast majority (we've sold 2M or so, the number of reports on HDMI issues is miniscule in comparison), but there's obviously something weird going on for a tiny number of people/devices. However, we have never been able to replicate any of the reported issues in the office which does make it difficult to debug, when you cannot make it go wrong.

What resolution are these devices?
I'm in the same boat as @Manos. The Pi4 has been very frustrating. If I take the SD card out of the Pi4 and put it in a Pi2 or 3b+, I have no problems at all. Those older boards work great.

My target TV is a brand new Vizio 32" (720p), model D32H-G9. The Pi2 and Pi3b+ both work perfectly fine, with no changes required to config.txt. While I have fiddled with config.txt, the 2/3b+ seem to do best when left alone to auto-negotiate the HDMI link, and the tv's OSD says the resolution is 1366x768. That's an expected value.

The Pi 4's behavior on this Vizio is a bit erratic. Rarely, I can get to the Pi desktop, but most of the time the screen is either black or a light purple with "No HDMI signal" message. No amount of fiddling with the config.txt has fixed the problem. Some forced CEA/DMT modes make it a little bit better (ie getting to the desktop consistently, even if the resolution/position/etc is screwy) - but nothing I do makes it behave correctly. Different Pi4 boards, different HDMI cables haven't helped. HDMI safe mode does "work", but obviously 640x480 is not the desired resolution.

For the sake of diagnostics, I also tried plugging into my Sony Bravia 4k TV (model XBR-65X810C) and the result was more or less the same. The Pi 4 boots, you can see the initial bootloader splash - row of raspberries, and I might get the initial OS splash - white box that says "raspberry pi desktop", then it seems as if maybe the Pi is changing video modes(?), tries to re-negotiate the HDMI link and fails. The left half of the screen ends up black, the right half is gray and nothing else happens. Swapped the SD card over to the 3b+, and it works perfectly and exactly as expected. For both 3b and 4b boards, the TV's OSD says it is in 1080p.

I would be happy to send you one of these Pi4 boards that I'm having a hard time with, or provide any sort of serial/lot numbers that might help. I can also pull any information from the Vizio TV's logic board (part numbers, etc) if that would help.

I've had great success with 2 and 3b boards for a few years now in a bunch of different projects, including some permanent installations using the same Vizio model TV. These 4b's not so much.

jamesh
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Fri May 08, 2020 8:04 am

1366x768 is the one mode we know doesn't work on the Pi4, because it's the only mode that has odd numbers in its timings, and the pi4 doesn't like odd timings. We do have an example monitor and are looking it to a way round it.

The odd number thing is because the HDMI HW now works at 2 pixels per clock, so having odd timings causes problems.
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Darren_L
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Fri May 08, 2020 9:02 am

Hello Jamesh,

Thanks for the info, I've tried easily 20 different modes and none of them work. Both CEA and DTM from VGA all the way up to 1080p. The pi reads the EDID fine but nothing displays. I've tried a Windows pc and that works fine with both inputs into the monitor. The second monitor (actually an old tv) works correctly with the handful of resolutions I've tried (apart from a flicker every minute that I haven't looked into). For some reason with the problem monitor I get no signal no matter what I do.

If i can get any debug info that would be useful just point me in the right direction.

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no3rpi
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Fri May 08, 2020 10:36 am

I have NO problems with rpi4 2Gb RAM running LibreElec and LG TV 55UK6500, it run ~12h every day.
Kodi run at 1080p 60Hz and LG tv upscale to 4k. CEC it is also working properly.
RPI3^2 + RPI4 = :idea:

sentineljones
Posts: 2
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Re: Pi 4 Model B. No output on LG TV. Tried everything.

Mon May 11, 2020 9:36 pm

jamesh wrote:
Fri May 08, 2020 8:04 am
1366x768 is the one mode we know doesn't work on the Pi4, because it's the only mode that has odd numbers in its timings, and the pi4 doesn't like odd timings. We do have an example monitor and are looking it to a way round it.

The odd number thing is because the HDMI HW now works at 2 pixels per clock, so having odd timings causes problems.
tbh, the 1366x768 thing in general annoys me. I don’t get why, especially in TVs, the people behind the format standards didn’t just stick to 720p - 1280x720. I guess it’s a cheaper(?) way to take a 4:3 1024x768 resolution and add some pixels to make it approximate 16:9. Computer monitors are a bit different beast than a TV (less so these days), so I expect them to sometimes have weird native resolutions. Weirdly, as someone else mentioned, Pi4 over HDMI to my Asus desktop monitors works fine. Maybe the monitors are more flexible and better at negotiating than the TVs because they have to be able to deal with a bazillion different graphics cards and other oddball field applications.

I ended up sending out my customer’s Vizio project with a 3b+. I still have the Pi4s and the aforementioned Sony 4K, so if I can provide any data to help am happy to do so. Would definitely like to eventually be able to use the more powerful Pi4 for non-headless(?) stuff.

I appreciate your engagement with us on this. It’s reassuring to hear from someone who’s knowledgeable, aware of, and looking at the problem.

Darren_L
Posts: 8
Joined: Mon May 04, 2020 9:47 am

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Wed Jun 03, 2020 11:35 am

Hello All,

Just wanted to reference my experience here, my issue turned out to be a faulty pi:

viewtopic.php?f=28&t=273020&p=1654810#p1654810

uberscubajim
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Location: Ipswich, Suffolk. UK.

Re: Pi 4 Model B. No output on LG TV. Tried everything.

Wed Jun 03, 2020 2:54 pm

Hi James and others,

I've seen this problem on multiple monitors. I'm using a Pi 4 with two 1920 by 1080 monitors and it took a long time to find two monitors that both worked. Even then one of them is occasionally dodgy.

The monitors are both connected using the official HDMI cables into HDMI to DVI couplers (they're passive).

Once lockdown is over I could even bring one of the failing monitors to Cambridge.

Regards,

Jim.

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