Just bought a pi 4B 8GB to use headless with access via ssvnc like I do with all my existing Pis.

Discovered the Pi 4B will not boot without a HDMI cable.

I have tried all the suggestions relating to /boot/config.txt and now the pi will not boot with or without a HDMI cable.

Any Ideas before I send it back with all the other stuff I bought to make use of this device ?

More Info as requested

The Buster image runs on two devices fitted with standard 7" touch screens. I have the specs but cannot cut and paste. One is Pi4B the other Pi3B. Both work and I can ssh and ssvnc.

If I put the Ultra SD card Buster image into a third Pi4B without an lcd or hdmi monitor it fails to boot. I cannot ssh. It also fails with a hdmi TV attached.

I removed the sd and reapplied the power and the hdmi reports:

Pi 4 - 8GB Bootloader: c305221a Sep 2020 Config:866970505 Board:d03114 60b004b1 xx:xx:xx:xx:xx:xx SD:Card not detected Part:0 mbr all zeros0000000000000000000000 Updates:enabled 0 fw: blank net:down ip: 00000000000000 gw: 000000000 tftp: 000000000

When I insert the card as requested, at last the Pi boots and all seems ok (ssh and ssvnv).

So if I then ssh in and do sudo shutdown 0, wait for activity to stop then remove the power and the hdmi cable and reapply the power I get the same problem.

The Pi4B still fails to boot without a hdmi monitor attached.

These are my /boot/config.txt settings. Sorry I cannot figure out how to cut and paster the entire file without it looking unreadable. I tried block quote and insert code without luck.

hdmi_force_hotplug=1 dtparam=i2c_arm=on dtparam=spi=on dtparam=audio=on under [all] enable_uart=0 dtoverlay=w1-gpio dtparam=i2c=on display_rotate=2

Please could someone tell me where to look to fix this ?

  • How do you know it is not booting? If you "tried all the suggestions" it must work.
    – Milliways
    Commented Mar 18, 2021 at 21:12
  • Hi thanks for your response. Not for me it seems. I cannot even ssh into the device. There is just a red led.I should be able to put an empty ssh file in /boot and working wpa_supplicant.conf into /boot
    – user131762
    Commented Mar 18, 2021 at 21:28
  • Unless you provide details e.g. the content of files all you will get is speculation
    – Milliways
    Commented Mar 18, 2021 at 21:39

3 Answers 3


The Pi4 should boot without a monitor connected. All my Pi do!

If you have other Pi which work, ensure they are fully updated.

Then take the SD Card and put in your Pi4 and it should boot.

NOTE while it is possible to set up a Pi without a monitor it is simpler to use a monitor for initial setup.

  • Hi, Thank you for the reassurance I will give it a go in the morning.
    – user131762
    Commented Mar 18, 2021 at 21:59
  • Thank you for your suggestion I verified the code runs on two devices but does not boot on a third device that is headless..
    – user131762
    Commented Mar 20, 2021 at 15:26
  • I can also say that the third device boots ok headless with a different vanilla Buster image.
    – user131762
    Commented Mar 20, 2021 at 15:28
  • When power is applied both red and green leds come on. The green led turns off quickly for about half a second and then it flashes on once before staying off for good. I cannot get any network access at all.
    – user131762
    Commented Mar 21, 2021 at 10:18
  • Could someone please check if this happens or not on anyone elses touch screen install when inserted into a headless Pi4b ?
    – user131762
    Commented Mar 21, 2021 at 10:23

@Milliways was right with the addition of fully UPGRADED. My image was fully updated and I was a bit scared of an apt-get upgrade but it all went perfect.

NOTE: After my upgrade it took a very long time to shutdown and restart.

Thank you for the reassurance, my confidence is fully restored.



I know that the question is considered answered, but just a few points ...

@Milliways was right with the addition of fully UPGRADED. My image was fully updated and I was a bit scared of an apt-get upgrade but it all went perfect.

in my machine apt's update/dist-upgrade happens always together. there are 2 reasons, someone maybe dont want to upgrade:

  1. User 'scared' ! -- So, the user must selecte an OS he trust!
  2. User install manually packages, and afraid a official system upgrade, will broke his setup. -- So what is more important, OS system stability and up todate, or custom setup. In the second case, user must know that, the security/stability of his OS is in his hand.

A good 'choice', in PIs, to get the boot cmd, is to run

cat /proc/cmdline

and not just cat the cmdline.txt from our /boot/ directory. In this way we will be able to see exactly the 'boot comand', that in a PI is depend on the /boot/config.txt

For a very simple network test, ncat can be use. ( of course a uart connection will be more ok, for a full control of pi), but

Thats how: In our host machine ( the pi will join its network), we run ncat as a sever. In the client host (PI) we just send something through ncat, (maybe in /etc/rc.local, or in cron.d/ ).

Here an pseudo example, using to terminals in my pc.

Terminal #1 (host machine)

ncat -lkp 3000
BOOT_IMAGE=/boot/vmlinuz-4.19.0-14-amd64 root=UUID=a49e4ff0-c36c-4db4-b77a-a6e74d754a3e ro quiet

Terminal #2 (pi)

cat /proc/cmdline| ncat 3000
  • the second line in Terminal#1, will happen after run the command in Terminal#2
  • the '' is the host machine address and must be supplied as per your setup

... anyway ;)

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