pramodjoshi
Posts: 4
Joined: Wed Dec 04, 2019 3:49 pm

No signal on HDMI port to Monitor

Wed Dec 04, 2019 4:02 pm

Hi,

I have 19M38HB LG Monitor and Raspberry Pi 4 Model B running Linux 4.19.75-v7l+ #1270 SMP, Raspbian.
I keep getting no signal when connected to the monitor.

Tried with various Config.txt setting.. hdmi_force_hotplug=1, hdmi_group=2 , hdmi_mode=81/4

hdmi_safe=1 also didn't help

***
# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode

hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=2
#hdmi_mode=81

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=1

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=9

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

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


[all]
#dtoverlay=vc4-fkms-v3d
#hdmi_enable_4kp60=1
****

Any suggestions?

renice123
Posts: 227
Joined: Tue Oct 15, 2019 3:56 pm

Re: No signal on HDMI port to Monitor

Wed Dec 04, 2019 6:16 pm

do the default settings not work?

Code: Select all

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1
#hdmi_group=2
#hdmi_mode=36
# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280

#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

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FTrevorGowen
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Joined: Mon Mar 04, 2013 6:12 pm
Location: Bristol, U.K.
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Re: No signal on HDMI port to Monitor

Wed Dec 04, 2019 8:49 pm

pramodjoshi wrote:
Wed Dec 04, 2019 4:02 pm
Hi,

I have 19M38HB LG Monitor and Raspberry Pi 4 Model B running Linux 4.19.75-v7l+ #1270 SMP, Raspbian.
I keep getting no signal when connected to the monitor.

Tried with various Config.txt setting.. hdmi_force_hotplug=1, hdmi_group=2 , hdmi_mode=81/4

hdmi_safe=1 also didn't help

...

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


[all]
#dtoverlay=vc4-fkms-v3d
#hdmi_enable_4kp60=1
****

Any suggestions?
1) Change the [pi4] section back to this please:

Code: Select all

pi@raspiP4B4b-32GbP:~ $ tail /boot/config.txt
dtparam=audio=on

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

[all]
#dtoverlay=vc4-fkms-v3d
ie. uncomment (remove the leading '#') on the #dtoverlay=vc4-fkms-v3d line

Can you (do you know how to?) enable the the SSH server so you can remotely log into the P4B from another computer (perhaps another Pi)?
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, 2xB2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, and a A+) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

pramodjoshi
Posts: 4
Joined: Wed Dec 04, 2019 3:49 pm

Re: No signal on HDMI port to Monitor

Thu Dec 05, 2019 1:56 am

Thanks Trev for the response.

I reset the config.txt to the default as suggested.
Modified the P4 section as suggested.
No luck, still no signal.

I can SSH as well as start and access the vncserver on Pi.

It is only that I need the display to work so that I can do away with all other computers in my setup..

Thanks,
Pramod

klricks
Posts: 7206
Joined: Sat Jan 12, 2013 3:01 am
Location: Grants Pass, OR, USA
Contact: Website

Re: No signal on HDMI port to Monitor

Thu Dec 05, 2019 2:06 am

pramodjoshi wrote:
Thu Dec 05, 2019 1:56 am
Thanks Trev for the response.

I reset the config.txt to the default as suggested.
Modified the P4 section as suggested.
No luck, still no signal.

I can SSH as well as start and access the vncserver on Pi.

It is only that I need the display to work so that I can do away with all other computers in my setup..

Thanks,
Pramod
This is what worked for me.
-Power down the RPi and remove USB power.
-Power down monitor/TV and remove mains (AC) power cord for a minute or 2.
-Power up the monitor/TV
-Power up the RPi.
Unless specified otherwise my response is based on the latest and fully updated RPiOS Buster w/ Desktop OS.

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FTrevorGowen
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Posts: 5725
Joined: Mon Mar 04, 2013 6:12 pm
Location: Bristol, U.K.
Contact: Website

Re: No signal on HDMI port to Monitor

Thu Dec 05, 2019 12:41 pm

pramodjoshi wrote:
Thu Dec 05, 2019 1:56 am
Thanks Trev for the response.

I reset the config.txt to the default as suggested.
Modified the P4 section as suggested.
No luck, still no signal.

I can SSH as well as start and access the vncserver on Pi.

It is only that I need the display to work so that I can do away with all other computers in my setup..

Thanks,
Pramod
Since you can SSH in to the Pi can you do so and post the output of these tvservice commands (with the display connected)?

Code: Select all

tvservice -n
tvservice -m DMT
tvservice -m CEA
tvservice -s
We may glean a few clues from that info.
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, 2xB2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, and a A+) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

pramodjoshi
Posts: 4
Joined: Wed Dec 04, 2019 3:49 pm

Re: No signal on HDMI port to Monitor

Thu Dec 05, 2019 2:20 pm

Hi,

Tried the unplugging / plugging sequence, but it didn't help.

Trev,
Output of the tvservice commands:

pi@rasp203:~ $ tvservice -n
device_name=GSM-LG_HD

pi@rasp203:~ $ tvservice -m DMT
Group DMT has 9 modes:
mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive
mode 6: 640x480 @ 75Hz 4:3, clock:31MHz progressive
mode 8: 800x600 @ 56Hz 4:3, clock:36MHz progressive
mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive
mode 11: 800x600 @ 75Hz 4:3, clock:49MHz progressive
mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive
mode 18: 1024x768 @ 75Hz 4:3, clock:78MHz progressive
(prefer) mode 81: 1366x768 @ 60Hz 16:9, clock:85MHz progressive
mode 85: 1280x720 @ 60Hz 16:9, clock:74MHz progressive

pi@rasp203:~ $ tvservice -m CEA
Group CEA has 7 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
(native) mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz 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

pi@rasp203:~ $ tvservice -s
state 0xa [HDMI CUSTOM RGB full 16:9], 1366x768 @ 60.00Hz, progressive

Regards,
Pramod

pramodjoshi
Posts: 4
Joined: Wed Dec 04, 2019 3:49 pm

Re: No signal on HDMI port to Monitor

Thu Dec 05, 2019 2:57 pm

Update:

I changed the following:

hdmi_safe=1
hdmi_mode=81
hdmi_drive=2

and connected the HDMI cable to HDMI 2

This works and I now able to use the Monitor.

Thanks all for your time and efforts.

Regards,
Pramod

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