Raspberry pi 4B doesn't boot anymore (kernel probably won't load)

[Etruscian]

I've had a lot of fun with my raspberry pi 4B 4GB version, but after a normal reboot sequence, it no longer boots. It does blink the green led indicating that the bootloader is running (no 4 blinks or anything), and then after 2 short blinks, it stops blinking and stops all activity. I've tried other sd cards, other flashers, nothing seems to work. I've updated the eeprom using the raspberry pi flasher, still no success.

I'm lost at the moment, does anybody know what I can do to make it work again? (all sd cards work on the raspberry pi 3 with no issue whatsoever).

[YTvW]

Do you have it connected to a network using a network cable?

[Etruscian]

I normally have, but I tried it with and without. It didn't make a difference.

[LTolledo]

does this setup look similar to yours?

RPi3A+_disaster-waiting-to-happen.jpg (174.95 KiB) Viewed 357 times

[YTvW]

are both the network lights stuck on when you have it plugged in?

[Etruscian]

That setup does not look similar to mine haha.

Both network lights are stuck. I just managed to get a micro hdmi to hdmi adapter and the screen is stuck at the rainbow screen. I've tried multiple sizes of sd cards, nothing seems to make any difference. All cards tested work fine on my rpi 3B. I've checked the voltages and 3v3 and 5v are spot on.

[YTvW]

whilst the setup does not look like mine, the rest is exactly as mine unfortunately

[Etruscian]

The cpu does get a little warm as if it's doing something. It's on the edge of not being comfortable anymore to hold my finger on it.

[Etruscian]

Another thing I noticed, if I load NOOBS on the SD card, it shows the rainbow screen on both hdmi ports. If I load anything else, it only shows it on 1 hdmi port (port 0).

[YTvW]

I took out the sd card and the roots partition is read only when trying to mount it in an ubuntu virtual machine

[procount]

I just managed to get a micro hdmi to hdmi adapter and the screen is stuck at the rainbow screen.

Do you mean in NOOBS or in some OS like Raspbian?
What colour is the top left hand square of the rainbow - red or magenta?

If it is magenta, you are plugged into the wrong HDMI socket. NOOBS ONLY uses HDMI-0 - the one next to the USB_C power socket.
If it is red, and stays there for more than 30 secs, then you have another problem.

[Etruscian]

On all OSes I tried, it's red. On noobs, when I connect it to HDMI 1, it's magenta and still red on HDMI 0. It stays there until I shut it down by disconnecting power.

[YTvW]

tried another sd card, and it boots fine, so something is not quite right with the filesystem in my case. rpi4 itself appears to be fine

[Etruscian]

With me, that is not the case. All SD cards I tried gave the same error...

[YTvW]

How did you create the sd cards? using the RPi imager, which os did you use

[Etruscian]

Using Etcher, Raspberry Pi Imager, manually copying NOOBS to the sd card. It all has the same outcome, while the cards all work fine on the rpi 3B I have.

[Etruscian]

My Pi can read the sd card fine, because EEPROM upgrade works btw

[Etruscian]

Small update.

I've attached an Arduino to UART0 of the raspberry pi and enabled uart_2ndstage in the config.txt. Then I'm using the Arduino IDE to read the serial lines. The output i'm getting is as follows:

Code: Select all

Initialising SDRAM 'Micron' 16Gb x2 total-size: 32 Gbit 3200
recover4.elf not found
recovery.elf not found
Read start4db.elf bytes  3743076 hnd 0x00003012 hash cd48e7ace6b4a741
Read fixup4db.dat bytes     8417 hnd 0x0000300f hash 8cc6cd1ae8897fd2
0x00c03112 0x00000000 0x0000000f
MEM GPU: 160 ARM: 864 TOTAL: 1024
FIXUP src: 128 256 dst: 864 1024
Starting start4db.elf @ 0xfec00200

(I've replaced the start4x.elf and fixup4x.dat with their debug versions which I got from the raspberry pi github and updated config.txt to reflect that to see if that would give me any more information).