dkeppens
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Joined: Wed Jan 23, 2019 11:18 am

RPI 4 video output

Sat Aug 31, 2019 3:16 pm

Ok, sorry, but another one of these

Tried connecting the new rpi4B to one HMDI screen. Not getting any output.
Tried all combinations of available hmdi ports on both devices. No effect.
Tried connecting to a newer output device instead of my old TV. No effect
I can see Buster is running in my dhcp logs. Ping is working.
Tried connecting no screens and ssh'ing into it. Connection refused which seems normal to me as i always had to enable ssh from a console connection before.

Anyone got any fresh ideas as to how to access it without an ssh connection so i can debug the screen problem ?

*sad face*

klricks
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Re: RPI 4 video output

Sat Aug 31, 2019 3:36 pm

dkeppens wrote:
Sat Aug 31, 2019 3:16 pm
...
Anyone got any fresh ideas as to how to access it without an ssh connection so i can debug the screen problem ?
Why not enable SSH by putting a ssh text file in the root of the SD card?
See #3 here: https://www.raspberrypi.org/documentati ... /README.md
Unless specified otherwise my response is based on the latest and fully updated Raspbian Buster w/ Desktop OS.

dkeppens
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Re: RPI 4 video output

Sat Aug 31, 2019 3:38 pm

Thanks. Looks great. You can have a cookie :-)

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FTrevorGowen
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Re: RPI 4 video output

Sat Aug 31, 2019 3:44 pm

dkeppens wrote:
Sat Aug 31, 2019 3:16 pm
Ok, sorry, but another one of these

Tried connecting the new rpi4B to one HMDI screen. Not getting any output.
Tried all combinations of available hmdi ports on both devices. No effect.
Tried connecting to a newer output device instead of my old TV. No effect
I can see Buster is running in my dhcp logs. Ping is working.
Tried connecting no screens and ssh'ing into it. Connection refused which seems normal to me as i always had to enable ssh from a console connection before.

Anyone got any fresh ideas as to how to access it without an ssh connection so i can debug the screen problem ?

*sad face*
1) It is (should be) possible to enable SSH w/o using raspi-config etc. see section 3 here: https://www.raspberrypi.org/documentati ... /README.md
2) You need to use HDMI0 (the one nearest the USB C power connector)
3) Are you seeing any form of display at all (eg. the four raspberries + text and the RGB splashscreen and then a blank screen) rather than, literally, nothing?
4) If you are seeing something but then getting a blank screen if you can access config.txt try commenting out dtoverlay=vc4-fkms-v3d in the [pi4] section so it looks like this:

Code: Select all

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
# dtoverlay=vc4-fkms-v3d
max_framebuffers=2
and report back.
5) If all else fails do you have (or have access to) a USB-to-TTL (3.3V) UART such as one of those shown here:
https://www.cpmspectrepi.uk/raspberry_p ... pters.html ?
Trev.
Edit. I see that @klricks has pipped me at the post w.r.t. 1) ;)
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

dkeppens
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Re: RPI 4 video output

Sat Aug 31, 2019 7:03 pm

FTrevorGowen wrote:
Sat Aug 31, 2019 3:44 pm
1) It is (should be) possible to enable SSH w/o using raspi-config etc. see section 3 here: https://www.raspberrypi.org/documentati ... /README.md

Yup, that worked, connected now.

2) You need to use HDMI0 (the one nearest the USB C power connector)

I am

3) Are you seeing any form of display at all (eg. the four raspberries + text and the RGB splashscreen and then a blank screen) rather than, literally, nothing?

Screen just stays slightly lit, but no output at all

4) If you are seeing something but then getting a blank screen if you can access config.txt try commenting out dtoverlay=vc4-fkms-v3d in the [pi4] section so it looks like this:

Code: Select all

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
# dtoverlay=vc4-fkms-v3d
max_framebuffers=2
and report back.

No changes

5) If all else fails do you have (or have access to) a USB-to-TTL (3.3V) UART such as one of those shown here:
https://www.cpmspectrepi.uk/raspberry_p ... pters.html ?
Trev.
Edit. I see that @klricks has pipped me at the post w.r.t. 1) ;)
Just the screen problem remaining now. Nothing special in dmesg. But so far can't get any output

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FTrevorGowen
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Re: RPI 4 video output

Sat Aug 31, 2019 11:16 pm

dkeppens wrote:
Sat Aug 31, 2019 7:03 pm
FTrevorGowen wrote:
Sat Aug 31, 2019 3:44 pm
1) It is (should be) possible to enable SSH w/o using raspi-config etc. see section 3 here: https://www.raspberrypi.org/documentati ... /README.md

Yup, that worked, connected now.

2) You need to use HDMI0 (the one nearest the USB C power connector)

I am

3) Are you seeing any form of display at all (eg. the four raspberries + text and the RGB splashscreen and then a blank screen) rather than, literally, nothing?

Screen just stays slightly lit, but no output at all

4) If you are seeing something but then getting a blank screen if you can access config.txt try commenting out dtoverlay=vc4-fkms-v3d in the [pi4] section so it looks like this:

Code: Select all

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
# dtoverlay=vc4-fkms-v3d
max_framebuffers=2
and report back.

No changes

5) If all else fails do you have (or have access to) a USB-to-TTL (3.3V) UART such as one of those shown here:
https://www.cpmspectrepi.uk/raspberry_p ... pters.html ?
Trev.
Edit. I see that @klricks has pipped me at the post w.r.t. 1) ;)
Just the screen problem remaining now. Nothing special in dmesg. But so far can't get any output
Since you can (now) ssh in what do these tvservice commands** report?

Code: Select all

tvservice -l
tvservice -n
tvservice -m DMT
tvservice -m CEA
tvservice -s

Trev.
** FWIW, see some notes (WIP) of mine here: http://www.cpmspectrepi.uk/raspberry_pi ... uster.html
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

dkeppens
Posts: 9
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Re: RPI 4 video output

Sun Sep 01, 2019 9:00 am

FTrevorGowen wrote:
Sat Aug 31, 2019 11:16 pm
Since you can (now) ssh in what do these tvservice commands** report?

Code: Select all

tvservice -l
tvservice -n
tvservice -m DMT
tvservice -m CEA
tvservice -s

Trev.
** FWIW, see some notes (WIP) of mine here: http://www.cpmspectrepi.uk/raspberry_pi ... uster.html
Hey Trev ,

[email protected]:~$ sudo bash
[email protected]:/home/dkeppens# tvservice -l
1 attached device(s), display ID's are :
Display Number 2, type HDMI 0
[email protected]:/home/dkeppens# tvservice -n
device_name=PHL-PhilipsTV__5_
[email protected]:/home/dkeppens# tvservice -m DMT
Group DMT has 15 modes:
mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive
mode 5: 640x480 @ 72Hz 4:3, clock:31MHz progressive
mode 6: 640x480 @ 75Hz 4:3, clock:31MHz progressive
mode 7: 640x480 @ 85Hz 4:3, clock:36MHz progressive
mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive
mode 10: 800x600 @ 72Hz 4:3, clock:50MHz progressive
mode 11: 800x600 @ 75Hz 4:3, clock:49MHz progressive
mode 12: 800x600 @ 85Hz 4:3, clock:56MHz progressive
mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive
mode 17: 1024x768 @ 70Hz 4:3, clock:75MHz progressive
mode 18: 1024x768 @ 75Hz 4:3, clock:78MHz progressive
mode 19: 1024x768 @ 85Hz 4:3, clock:94MHz progressive
(prefer) mode 22: 1280x768 @ 60Hz 15:9, clock:68MHz progressive
mode 35: 1280x1024 @ 60Hz 5:4, clock:108MHz progressive
mode 39: 1360x768 @ 60Hz 16:9, clock:85MHz progressive
[email protected]:/home/dkeppens# 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
mode 6: 720x480 @ 60Hz 4:3, clock:27MHz x2 interlaced
mode 7: 720x480 @ 60Hz 16:9, clock:27MHz x2 interlaced
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
(native) 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
mode 22: 720x576 @ 50Hz 16:9, clock:27MHz x2 interlaced
mode 31: 1920x1080 @ 50Hz 16:9, clock:148MHz progressive
[email protected]:/home/dkeppens# tvservice -s
state 0xa [HDMI DMT (22) RGB full 15:9], 1280x768 @ 60.00Hz, progressive
[email protected]:/home/dkeppens#

Sorry, not really at home in the video stuff. Am used to working on headless servers

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FTrevorGowen
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Re: RPI 4 video output

Sun Sep 01, 2019 2:42 pm

dkeppens wrote:
Sun Sep 01, 2019 9:00 am
...
Hey Trev ,

[email protected]:~$ sudo bash
[email protected]:/home/dkeppens# tvservice -l
1 attached device(s), display ID's are :
Display Number 2, type HDMI 0
[email protected]:/home/dkeppens# tvservice -n
device_name=PHL-PhilipsTV__5_
[email protected]:/home/dkeppens# tvservice -m DMT
Group DMT has 15 modes:
mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive
mode 5: 640x480 @ 72Hz 4:3, clock:31MHz progressive
mode 6: 640x480 @ 75Hz 4:3, clock:31MHz progressive
mode 7: 640x480 @ 85Hz 4:3, clock:36MHz progressive
mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive
mode 10: 800x600 @ 72Hz 4:3, clock:50MHz progressive
mode 11: 800x600 @ 75Hz 4:3, clock:49MHz progressive
mode 12: 800x600 @ 85Hz 4:3, clock:56MHz progressive
mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive
mode 17: 1024x768 @ 70Hz 4:3, clock:75MHz progressive
mode 18: 1024x768 @ 75Hz 4:3, clock:78MHz progressive
mode 19: 1024x768 @ 85Hz 4:3, clock:94MHz progressive
(prefer) mode 22: 1280x768 @ 60Hz 15:9, clock:68MHz progressive
mode 35: 1280x1024 @ 60Hz 5:4, clock:108MHz progressive
mode 39: 1360x768 @ 60Hz 16:9, clock:85MHz progressive
[email protected]:/home/dkeppens# 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
mode 6: 720x480 @ 60Hz 4:3, clock:27MHz x2 interlaced
mode 7: 720x480 @ 60Hz 16:9, clock:27MHz x2 interlaced
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
(native) 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
mode 22: 720x576 @ 50Hz 16:9, clock:27MHz x2 interlaced
mode 31: 1920x1080 @ 50Hz 16:9, clock:148MHz progressive
[email protected]:/home/dkeppens# tvservice -s
state 0xa [HDMI DMT (22) RGB full 15:9], 1280x768 @ 60.00Hz, progressive
[email protected]:/home/dkeppens#

Sorry, not really at home in the video stuff. Am used to working on headless servers
The good news - tvservice -s reports that the Pi has found and selected the preferred DMT mode, so should be displaying. Since you've still got a blank screen it's possible it's a "HDMI drive level" issue (is your cable quite long?). What happen if you try other config_hdmi_boost levels (>4) in config.txt (see here for more info. https://www.raspberrypi.org/documentati ... t/video.md )?
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

andrum99
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Re: RPI 4 video output

Sun Sep 01, 2019 5:14 pm

config_hdmi_boost is not yet implemented on Pi 4. I think there are two realistic possibilities:

1. The Pi 4 has selected the wrong video mode, and the monitor is refusing to display anything. Which would be odd, as it is one of the modes returned by the EDID.

2. The cable or adaptor is faulty - the DDC pins are working, but at least one of the TMDS pairs are not.

Or it could be something else. So I would try using a different cable to connect the Pi 4 to the screen. If you are using a micro-HDMI to HDMI adaptor, try a different one of those as well, or try one of the official micro-HDMI to HDMI cables.

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FTrevorGowen
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Re: RPI 4 video output

Sun Sep 01, 2019 5:31 pm

andrum99 wrote:
Sun Sep 01, 2019 5:14 pm
config_hdmi_boost is not yet implemented on Pi 4. I think there are two realistic possibilities:
...
Sorry, my bad, "forgot" we're talking about a P4B (late night yesterday!) :oops:
The odd thing is that disabling fkms, which should, effectively, cause a P4B to behave more like "older Pi's" , apart from the "Buster" factor - Buster handles edid's differently to older Raspbian versions but, AIUI, only after the initial "4 raspberries/console display. The latter not showing made me think of HDMI drive issues).
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

dkeppens
Posts: 9
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Re: RPI 4 video output

Sun Sep 01, 2019 7:06 pm

Thanks guys. I'll try hooking it up to another screen again i guess. I am using a micro-to-hdmi cable though, not an adapter, and a new one to boot. Not a long cable either. No idea what the issue is...

ethanpi
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Re: RPI 4 video output

Fri Sep 27, 2019 4:52 pm

Have you been able to identify what the problem could be. I have a new Pi4, new power, new micro HDMI, I connect it all, the power, Act LED is on, Ethernet port LED's are on, but my screen is blank. I've tried both output ports, rebooted with the screen active and no output on my screen.

As this is my first boot, I don't know how to get a remote login, i had a look on my router and I suppose because the setup has not taken place yet, there is no IP address.

Any ideas what to do?

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mahjongg
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Re: RPI 4 video output

Fri Sep 27, 2019 4:58 pm

read the RPI4 section of the boot problem sticky.

use HDMI-0 not HDMI-1

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