RPI 4 boot problem not listed in the sticky post

[Anelit0]

I know this kind of problem is extremely common and dozens of questions have been asked but I still can't figure out why my new Pi 4 isn't booting.

The first time I used the RPI4 I succeeded to boot but soon after that the system crashed with a kernel error. I though it was a download problem, so I got a fresh Raspian version. After that, only a solid red light will show up. Apparently, the boot process is performed as for around 30s the green led is randomly flashing, but after that the Pi is dead, not showing up in the local ip list nor giving any output on the screen.
I am using adequate power supply, HDMI0 port and the official latest Raspian release (feb 2020) on multiple microSD 16GB cards; I also tried to toggle HDMI safe and other settings in config.txt.

I tried the EEPROM test suggested in the sticky post booting without microSD card and I get the 4 green led flashes. I successfully followed the recovery procedure downloading the newest bootloader but it didn't change anything.
Is there a Serial port or some other way to debug and understand what is really happening? If the PI is faulty, as I suspect, can I return it?

[pcmanbob]

So how is your pi connected to your network ?

I would suggest you use a wired connection as that should connect automatically, do you see the LEDs on the network port on the pi flashing to indicate traffic.

One way to see if the pi is booting is with a fresh install of raspbian on an SD card , while the SD card is still in your pc add a file call ssh or ssh.txt, then after trying to boot for the SD card power down your pi put the SD card back in the PC , if the file ssh is still present your pi did not finish booting , if its not present then it must have got a fare way in to the boot process.

There is a serial console available on gpio pins 14,15 , having never used it all I can off is this link

https://elinux.org/RPi_Serial_Connection

there are several users on here that use it regularly hopefully one of them will be able to off more help.

As for returning your pi you need to speak to your supplier as any return would be handled by them.

[Anelit0]

I always create the SSH file and connect the Pi via ethernet, as expected it doesn't appear as on the network.

[pcmanbob]

I always create the SSH file and connect the Pi via ethernet, as expected it doesn't appear as on the network.

So does the SSH file disappear ?

What are the LAN port LEDs doing on/off/flashing ?

[Anelit0]

No the SSH file is there and the LAN leds are both on (a yellow and a green one)

[FTrevorGowen]

W.r.t. using a USB-to-TTL(3.3V) serial adapter FWIW there are some (old) notes of mine about various (not all suitable) devices here:
https://www.cpmspectrepi.uk/raspberry_p ... pters.html
The P4B I'm posting from has the serial console enabled (+ other things) and its /boot/cmdline.txt looks like this:

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pi@raspiP4B4b-32GbP:~ $ cat /boot/cmdline.txt
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=PARTUUID=e3269cea-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait video=HDMI-A-1:1920x1080@60,margin_left=32,margin_right=38,margin_top=32,margin_bottom=28

What have connected HDMI0 to (if anything), true monitor or T.V.?
If the eeprom is "fully" updated you may/should get a diagnostic screen output to the display even if you try booting w/o a (valid) uSDHC card.
Something like this (where the card had missing/invalid files):

P1100072c.JPG (55.34 KiB) Viewed 913 times

Trev.

[Anelit0]

Ok that's interesting.
I tried to update my cmdline but still can't get any response, either SSH console or video output. No boot screen without card wither, I only get the 4 green flashes.
I'm using a standard HDMI monitor, for PCs.

[FTrevorGowen]

Ok that's interesting.
I tried to update my cmdline but still can't get any response, either SSH console or video output. No boot screen without card wither, I only get the 4 green flashes.
I'm using a standard HDMI monitor, for PCs.

Hmm. Can you try a different uHDMI-to-HDMI cable or are you using an adapter? How (physically) are you writing the O.S. (Raspbian?) to the card?
Trev.

[Anelit0]

I tried the adapter cable with a Raspberry Pi Zero and it seems to be ok. Anyway, even if it were a cable/monitor problem, the Raspberry would still appear on the local network.
I'm using Etcher, so far it has worked seamlessly.

[FTrevorGowen]

I tried the adapter cable with a Raspberry Pi Zero and it seems to be ok. Anyway, even if it were a cable/monitor problem, the Raspberry would still appear on the local network.
I'm using Etcher, so far it has worked seamlessly.

Since a Zero uses a mini-HDMI connector and the P4B a micro-HDMI one I'm guessing you're using two adapters. Some micro-HDMI adapters are known not to work well with the P4B and since the test I suggested means that no O.S. would have been loaded the P4B would not appear on the network.
Trev.

[pcmanbob]

Since the OP's pi4 was working at some point as stated in their first post , and now it seems to not be booting in any way, I rather think that it is another spontaneous failure which a few pi4 seem to suffer, my be it's time to speak to your supplier about a replacement.

[Anelit0]

I succeeded in booting once, still no HDMI signal but I did log in via ssh.
However, the booting is non deterministic, sometimes it just fails and goes into halt mode.
How do I know if it is a faulty Pi?

[FTrevorGowen]

I succeeded in booting once, still no HDMI signal but I did log in via ssh.
However, the booting is non deterministic, sometimes it just fails and goes into halt mode.
How do I know if it is a faulty Pi?

On re-reading your O.P. what, exactly, is your "adequate power supply"?
Trev.

[Anelit0]

USB power adapter with max output 5V 3.0A

[FTrevorGowen]

USB power adapter with max output 5V 3.0A

An "official one" with a fixed cable like these: https://www.cpmspectrepi.uk/raspberry_p ... ne_2019.29
or a "generic" USB C Charger/PSU with a separate cable like this: https://www.cpmspectrepi.uk/raspberry_p ... .2FCharger ?
If the latter, how long is the cable?
Trev.

[Anelit0]

it is a Sony AC adapter savaged from a nephew's playstation. Wall plug input, usb output. I checked working conditions with a USB multimeter, 5-5.11V output voltage while output current oscillating between 0.5 to 3A depending on the load applied.

[FTrevorGowen]

it is a Sony AC adapter savaged from a nephew's playstation. Wall plug input, usb output. I checked working conditions with a USB multimeter, 5-5.11V output voltage while output current oscillating between 0.5 to 3A depending on the load applied.

Probably "not good enough" for the job. A multimeter will not show transient loading behaviour and whether any significant ripple is present. It's possible that a transient voltage drop caused your kernel error. If it also exhibits transient voltage spikes (which would have been smoothed out by "larger" capacitors in the playstation) it's also possible that the P4B has been damaged. Whilst some, modern USB3 C power supplies can be used to power a P4B with the correct connecting tables the official supplies are the "best ones for the job"!
Trev.

[Biblioman]

I succeeded in booting once, still no HDMI signal but I did log in via ssh.
However, the booting is non deterministic, sometimes it just fails and goes into halt mode.
How do I know if it is a faulty Pi?

The same thing happens to me as to you, I thought it was the power supply but I have acquired the official RPI and it does the same thing I have got it to start once by uncommenting the following line in config.txt:
arm_freq=800

(I also have the 4G RPI4 v 1.2)
Any recommendations for config.txt?

[Biblioman]

Checked by lowering the frequency to the CPU stays stable
arm_freq=700
Any idea what that might be? ... A new bug for RPI4 4G v1.2

[HawaiianPi]

Is there a Serial port or some other way to debug and understand what is really happening?

There is a serial port, and the shell output can be redirected to the serial console with a few simple file edits to a Raspbian imaged SD card. It's a really handy debugging tool that allows you to monitor the output during boot, and to login without a network connection.

You'll need a serial console cable or USB-TTL UART adapter with 3.3V TTL. I use inexpensive CP2102 adapters from eBay that cost less than $2, but the slow shipping would not be helpful in your current situation. You can order serial console cables from most Raspberry Pi resellers (assuming they're not closed due to the pandemic).

If you want to pursue this further I can offer additional help. Let me know.

[Anelit0]

An update.
I've been reflashing the microSD cards over this weeks and by an empirical analysis I can get Raspian to work a few times, but every time upon reboot the Raspberry Pi4 goes back into a no input/no output state.
Before you ask, multiple 16/32GB microSD cards have been used, the latest version of Raspian used, Balenaetcher and dd for flashing.

Update:
kernel error after a

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sudo apt upgrade

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Preparing to unpack .../173-xfce4-power-manager-data_1.6.6-1_all.deb ...
Unpacking xfce4-power-manager-data (1.6.6-1) over (1.6.5-2) ...

[Anelit0]

Anyone?

The seller refused to give a replacement saying it is the manufacturer's responsibility (the Raspberry Pi foundation).

[cleverca22]

take a directory listing of the fat32 partition immediately after you flash the card, and then again once it fails to boot

what files have changed? did any get added?

have you tried the uart adapter yet to see any logs on the serial port?

[Anelit0]

I used git, before and after boot on a fresh install and there were no files created.
Here is the result:

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Binary file /dev/null differ

The Ethernet green LED was on but there was no screen output nor ssh port open.

How to connect to UART for debugging purposes?

[HawaiianPi]

Anyone?

The seller refused to give a replacement saying it is the manufacturer's responsibility (the Raspberry Pi foundation).

Not true. Warranty is handled through the seller. Unless you didn't buy from an authorized Raspberry Pi reseller, then ¯\_(ツ)_/¯