LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 2:39 am

good evening,

i have a new RP4, and i haven't yet gotten it to drive a monitor or my projector.

running Debian Buster, everything else functions as expected. just nothing on any monitor or my projector.

Code: Select all

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

Code: Select all

tvservice -n
device_name=GSM-LG_PROJECTOR
which is correct !

running tvservice -m DMT -v 2
returns the correct resolution options for the projector.

editing my /boot/config.txt i have un-commented the following :

Code: Select all

hdmi_force_hotplug=1
hdmi_group=2
hdmi_mode=82
config_hdmi_boost=4
dtparam=audio=on
max_framebuffers=2
all other options are commented out.

i'm at a loss.
the RP4 is obviously able to see the projector to pull the EDID info, but it's refusing to send video.
any help would be greatly appreciated :)

aBUGSworstnightmare
Posts: 1855
Joined: Tue Jun 30, 2015 1:35 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 4:36 am

config_hdmi_boost is ignored on the RPI4
Why do you need ro use hdmi_force_hotplug?
Fix the typo in dtparam=audio=on -> dtparam-audio=on Mod removed this as incorrect.
All details on video settings are here https://www.raspberrypi.org/documentati ... t/video.md

Make sure your projector is connected to HDMI0 (the socket next to USB-C)

DirkS
Posts: 10345
Joined: Tue Jun 19, 2012 9:46 pm
Location: Essex, UK

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 5:12 am

aBUGSworstnightmare wrote:
Tue Apr 21, 2020 4:36 am
Fix the typo in dtparam=audio=on -> dtparam-audio=on
FTFY
AFAIK all the dtparams are in the form 'dtparam='.

LTolledo
Posts: 3273
Joined: Sat Mar 17, 2018 7:29 am
Location: Anime Heartland

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 9:21 am

what is the native resolution of the monitor and/or projector?
"Don't come to me with 'issues' for I don't know how to deal with those
Come to me with 'problems' and I'll help you find solutions"

Some people be like:
"Help me! Am drowning! But dont you dare touch me nor come near me!"

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26397
Joined: Sat Jul 30, 2011 7:41 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 10:46 am

Dump the EDIT using

Code: Select all

tvservice -d edid.bin
Encode as base64

Code: Select all

base64 edid.bin
Post the resulting text dump here.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 1:23 pm

jamesh wrote: Post the resulting text dump here.
i was required to sudo that command, could this be a permissions issue ?

i haven't needed to sudo any of the other tvservice commands, but i'm not usually in the /boot folder, either.

Code: Select all

pi@raspberrypi:/boot $ sudo tvservice -d edid.bin
Written 256 bytes to edid.bin
pi@raspberrypi:/boot $ sudo base64 edid.bin
AP///////wAebQEAAQEBAQEZAQOAoFp4Cu6Ro1RMmSYPUFShCAAxQEVAYUBxQIGAAQEBAQEBAjqA
GHE4LUBYLEUAQIRjAAAeZiFQsFEAGzBAcDYAQIRjAAAeAAAA/QA6Ph5TEAAKICAgICAgAAAA/ABM
RyBQUk9KRUNUT1IKAbgCAyPxSJAiIAUEAwIBKT0GwBUHUAlXB2cDDAAQALgt4wUAAAI6gBhxOC1A
WCwEBUCEYwAAHgEdgBhxHBYgWCwlAECEYwAAngEdAHJR0B4gbihVAECEYwAAHowK0Iog4C0QED6W
AECEYwAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAWg==
pi@raspberrypi:/boot $
thanks for your help.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 1:24 pm

LTolledo wrote:
Tue Apr 21, 2020 9:21 am
what is the native resolution of the monitor and/or projector?
1920 x 1080

it will still show sources below that resolution, just complains about them not being the native.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 1:27 pm

aBUGSworstnightmare wrote:
Tue Apr 21, 2020 4:36 am
config_hdmi_boost is ignored on the RPI4
Why do you need ro use hdmi_force_hotplug?
Fix the typo in dtparam=audio=on -> dtparam-audio=on Mod removed this as incorrect.
All details on video settings are here https://www.raspberrypi.org/documentati ... t/video.md

Make sure your projector is connected to HDMI0 (the socket next to USB-C)
used the hdmi_force_hotplug while trying to solve this problem, from looking at other folks' solutions.

thought maybe the Pi was resorting to composite video because it booted before plugging in to the monitor. unfortunately, restarting it several times after making config changes, with the projector attached, didn't make any difference.

the projector is connected to HDMI0, as shown by tvservice identifying it.

thanks for your help.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 1:29 pm

DirkS wrote:
Tue Apr 21, 2020 5:12 am
aBUGSworstnightmare wrote:
Tue Apr 21, 2020 4:36 am
Fix the typo in dtparam=audio=on -> dtparam-audio=on
FTFY
AFAIK all the dtparams are in the form 'dtparam='.
the audio param was set by the rasp-configurator tool, i didn't enter than one manually.

thanks

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 1:48 pm

At first glance that EDID looks OK. There is an error that a block is badly terminated, but everything else seems OK. Running though the Pi parser and it choses CERA mode 16, which is 1920x1080.

Only thing that is ringing a bell is that it claims to support YCbCr 4:4:4 and YCbCr 4:2:2, need to check those are OK.. Also says at another point RGB 4:4:4.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 1:59 pm

jamesh wrote:
Tue Apr 21, 2020 1:48 pm
At first glance that EDID looks OK. There is an error that a block is badly terminated, but everything else seems OK. Running though the Pi parser and it choses CERA mode 16, which is 1920x1080.

Only thing that is ringing a bell is that it claims to support YCbCr 4:4:4 and YCbCr 4:2:2, need to check those are OK.. Also says at another point RGB 4:4:4.
thanks for checking.

is the badly terminated block something i can fix or recompile on my end ?

i commented out hdmi_group=2 and hdmi_mode=82 to see if the RP4 would get the correct chroma settings without my forcing resolutions, and it is still not sending video to the projector. after commenting those lines out, i no longer get the correct resolutions available when i run tvservice -m DMT -v 2

what's the next step to try and get this RP4 to send video from the HDMI port ?

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26397
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Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 3:20 pm

LingHood wrote:
Tue Apr 21, 2020 1:59 pm
jamesh wrote:
Tue Apr 21, 2020 1:48 pm
At first glance that EDID looks OK. There is an error that a block is badly terminated, but everything else seems OK. Running though the Pi parser and it choses CERA mode 16, which is 1920x1080.

Only thing that is ringing a bell is that it claims to support YCbCr 4:4:4 and YCbCr 4:2:2, need to check those are OK.. Also says at another point RGB 4:4:4.
thanks for checking.

is the badly terminated block something i can fix or recompile on my end ?

i commented out hdmi_group=2 and hdmi_mode=82 to see if the RP4 would get the correct chroma settings without my forcing resolutions, and it is still not sending video to the projector. after commenting those lines out, i no longer get the correct resolutions available when i run tvservice -m DMT -v 2

what's the next step to try and get this RP4 to send video from the HDMI port ?
Have you tried on other devices? Do we know it actually works before using it on the projector?
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 4:32 pm

jamesh wrote:
Tue Apr 21, 2020 3:20 pm
Have you tried on other devices? Do we know it actually works before using it on the projector?
i haven't gotten this RP4 to ever send video out of either HDMI port to anything, unfortunately.

i bought a replacement cable for the micrHDMI cable i already had, hoping that it was an issue with the cable.

the projector is known to be working, because i'm trying to replace the tablet that has been using it, with the RP4.

i've just moved the RP4 to my office and connected to a known good Dell monitor, and re-enabled safe_hdmi=1 :

Code: Select all

pi@raspberrypi:~ $ tvservice -l
2 attached device(s), display ID's are :
Display Number 2, type HDMI 0
Display Number 7, type HDMI 1
pi@raspberrypi:~ $ tvservice -n
device_name=DEL-DELL_U2412M
pi@raspberrypi:~ $
the Pi is correctly recognizing the Dell monitor, and is able to identify it.

Still no video being sent.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26397
Joined: Sat Jul 30, 2011 7:41 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 4:56 pm

LingHood wrote:
Tue Apr 21, 2020 4:32 pm
jamesh wrote:
Tue Apr 21, 2020 3:20 pm
Have you tried on other devices? Do we know it actually works before using it on the projector?
i haven't gotten this RP4 to ever send video out of either HDMI port to anything, unfortunately.

i bought a replacement cable for the micrHDMI cable i already had, hoping that it was an issue with the cable.

the projector is known to be working, because i'm trying to replace the tablet that has been using it, with the RP4.

i've just moved the RP4 to my office and connected to a known good Dell monitor, and re-enabled safe_hdmi=1 :

Code: Select all

pi@raspberrypi:~ $ tvservice -l
2 attached device(s), display ID's are :
Display Number 2, type HDMI 0
Display Number 7, type HDMI 1
pi@raspberrypi:~ $ tvservice -n
device_name=DEL-DELL_U2412M
pi@raspberrypi:~ $
the Pi is correctly recognizing the Dell monitor, and is able to identify it.

Still no video being sent.
You should not need to make any changes to config.txt to get HDMI out, so remove anything you have changed, then retry. If it doesn't work, then the Pi is probably broken, and needs to be replaced under warranty.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Tue Apr 21, 2020 5:27 pm

jamesh wrote:
Tue Apr 21, 2020 4:56 pm
You should not need to make any changes to config.txt to get HDMI out, so remove anything you have changed, then retry. If it doesn't work, then the Pi is probably broken, and needs to be replaced under warranty.
commented everything out of the /boot/config.txt , get the same correct monitor identification after a reboot.

still no video.

is there any possibility that this is an issue that could be solved by updating any firmware ? or an incorrect boot image ?

i bought the Pi from Amazon, would i need to go through the seller for a warranty replacement ?

thanks for your continuing assistance.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26397
Joined: Sat Jul 30, 2011 7:41 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Wed Apr 22, 2020 7:34 am

LingHood wrote:
Tue Apr 21, 2020 5:27 pm
jamesh wrote:
Tue Apr 21, 2020 4:56 pm
You should not need to make any changes to config.txt to get HDMI out, so remove anything you have changed, then retry. If it doesn't work, then the Pi is probably broken, and needs to be replaced under warranty.
commented everything out of the /boot/config.txt , get the same correct monitor identification after a reboot.

still no video.

is there any possibility that this is an issue that could be solved by updating any firmware ? or an incorrect boot image ?

i bought the Pi from Amazon, would i need to go through the seller for a warranty replacement ?

thanks for your continuing assistance.
Assuming a correctly imaged card, if it doesn't work out of the box, with multiple different and standard devices, there's nothing that can be done. All warranties are with the seller.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Wed Apr 22, 2020 1:00 pm

jamesh wrote:
Wed Apr 22, 2020 7:34 am

Assuming a correctly imaged card, if it doesn't work out of the box, with multiple different and standard devices, there's nothing that can be done. All warranties are with the seller.
i can only assume the image is correct, since the Pi boots normally, and has been running a LAMP stack for a month. i can remote in via SSH for command line control, or via RDP to use the XFCE desktop.

i've reached out to the seller, who has agreed to test and replace the unit.

thanks.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 2:35 am

jamesh wrote:
Wed Apr 22, 2020 7:34 am
You should not need to make any changes to config.txt to get HDMI out, so remove anything you have changed, then retry. If it doesn't work, then the Pi is probably broken, and needs to be replaced under warranty.

....

Assuming a correctly imaged card, if it doesn't work out of the box, with multiple different and standard devices, there's nothing that can be done. All warranties are with the seller.
good evening,

i returned the Pi to the seller, and they reported that they simply plugged the Pi in with an image of NOOBS and the video worked perfectly. they offered to send it back, but specified that i wouldn't be able to return it if i encountered more problems, so i just got a refund.

a week later i ordered a new RP4 from a different vendor, and - again - i have NO video.

same exact symptoms as before... the Pi boots normally and functions normally over the network, but refuses to push video.

i've dug my old flat screen TV out, which lets me plug the micro-HDMI in directly, without any extension cable or adapter, and still nothing.

i pulled the microSD card out, plugged it into my RP0w, and the Pi0w works perfectly with the screen.

the only possible culprit is the HDMI cables... but i've got two new ones from two different vendors, and it seems hugely unlikely they would both fail while still working sufficiently to let the RP4 identify the screen. i bought a Rankie micro-HDMI cable, and there are lots of reviews of people using it with RP4b's.

is my only option to keep buying micro HDMI cables ? am i just too dumb to get a RP4 to send video ??

the odds of two bad RP4's which only fail to push video, seems impossibly low. as does the odds of two quasi-failed HDMI cables.

i'm at a loss. is there any command line options i could perform over the network to do a HDMI cable test with the RP4 ?

andrum99
Posts: 1186
Joined: Fri Jul 20, 2012 2:41 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 10:54 am

Can you try with a blank SD card, imaged with the latest version of Raspbian using the Raspberry Pi Imager from https://www.raspberrypi.org/downloads/? Boot the Pi 4 with that card and only the Dell monitor attached - there's no reason why that should not work. If it doesn't, try different cables.

aBUGSworstnightmare
Posts: 1855
Joined: Tue Jun 30, 2015 1:35 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 11:31 am

Hi, can you do me a vavour and provide more details on your monitor? Googeling for DELL_U2412M gives the result this is a 1920x1080pixel resolution and has NO HDMI input (only DVI, DP and VGA).
So knowing more details might help.

andrum99
Posts: 1186
Joined: Fri Jul 20, 2012 2:41 pm

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 1:04 pm

aBUGSworstnightmare wrote:
Mon May 25, 2020 11:31 am
Hi, can you do me a vavour and provide more details on your monitor? Googeling for DELL_U2412M gives the result this is a 1920x1080pixel resolution and has NO HDMI input (only DVI, DP and VGA).
So knowing more details might help.
Actually it says 1920x1200. (See https://www.dell.com/is/business/p/dell-u2412m/pd). The DVI is DVI-D so presumably the OP is using an adaptor cable. There should be no problem with using an adaptor cable, assuming the cable is working.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 3:00 pm

aBUGSworstnightmare wrote:
Mon May 25, 2020 11:31 am
Hi, can you do me a vavour and provide more details on your monitor? Googeling for DELL_U2412M gives the result this is a 1920x1080pixel resolution and has NO HDMI input (only DVI, DP and VGA).
So knowing more details might help.
good morning,

yes, i can confirm the Dell u2412m has no native HDMI support. i have several known good (they're in daily use) HDMI >> DVI cables, but none of them worked for either the RP4 or my RP0w. i suspected the RP0w had a bad disk image, so i don't think it was working regardless, but the RP4 should have worked. i have just flashed a new Buster image to the sdcard for the RP0w, and it works with the dell monitor without any modification of any configuration files.

previously, with my original RP4, the pi was able to correctly identify the Dell monitor when it was connected, including correct available resolutions via tvservice

Code: Select all

pi@raspberrypi:~ $ tvservice -l
2 attached device(s), display ID's are :
Display Number 2, type HDMI 0
Display Number 7, type HDMI 1
pi@raspberrypi:~ $ tvservice -n
device_name=DEL-DELL_U2412M
pi@raspberrypi:~ $
i have not tried this yet with the new RP4, since i haven't enabled wifi yet.

i can confirm when i take the sdcard out of the RP0w, and plug it into the RP4, and boot the RP4, i get no video on the same monitor.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 3:14 pm

andrum99 wrote:
Mon May 25, 2020 1:04 pm
aBUGSworstnightmare wrote:
Mon May 25, 2020 11:31 am
Hi, can you do me a vavour and provide more details on your monitor? Googeling for DELL_U2412M gives the result this is a 1920x1080pixel resolution and has NO HDMI input (only DVI, DP and VGA).
So knowing more details might help.
Actually it says 1920x1200. (See https://www.dell.com/is/business/p/dell-u2412m/pd). The DVI is DVI-D so presumably the OP is using an adaptor cable. There should be no problem with using an adaptor cable, assuming the cable is working.
i have confirmed the HDMI to DVI cable works with my RP0w, and confirmed that the female/female HDMI connector works with the RP0w.
both items are in daily use for my laptop, but i had not yet confirmed function for any Pi device. still no luck with the RP4.

i'm charging my dSLR, which is the only other appliance i have which has the micro-HDMI port.

i'll be able to confirm if the micr-HDMI cables work in another hour or two. the vendor has already confirmed that the micro-HDMI cables should work for RP4.

LingHood
Posts: 13
Joined: Tue Apr 21, 2020 2:15 am

Re: Another RP4 failing to drive a screen via HDMI0 thread

Mon May 25, 2020 8:23 pm

andrum99 wrote:
Mon May 25, 2020 10:54 am
Can you try with a blank SD card, imaged with the latest version of Raspbian using the Raspberry Pi Imager from https://www.raspberrypi.org/downloads/? Boot the Pi 4 with that card and only the Dell monitor attached - there's no reason why that should not work. If it doesn't, try different cables.
good afternoon,

my camera finally charged, and i was able to confirm both of my micro-hdmi cables work. zero problems sending pictures to my monitor or TV using my OM-D camera and the micro-hdmi cables.

i downloaded the current version of RP Imager, and the Raspian Buster Full image, and reformatted the same microSD card i've been using, before imaging it.

i get the regular boot sequence LED lights from the RP4, zero video on the monitor... tried both of the micro-HDMI cables in port0 - closest to power.

pulled the microSD from the RP4 and plugged it into my RP0w, and it booted fine, so i know the image on the card is good.

i've verified the memory card and OS are good, verified the micro-HDMI cables are good, already spend $15 to return my original RP4, and now have another one that i can't get video from.

at this point i'm ready to just return all the raspberry materials that i can, and go with something from Odroid.

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