My Pi4B wouldn't boot up the other day and have been trying many different things with no luck. I have everything unplugged from it except the official power supply. With or without the SD card inserted I'm getting 3 long followed by 3 short flashes of the green led and a solid red.

I got a brand new SD card (San Disk Extreme 32Gb) and burned latest Rasbian using PiImager and I am getting the same behavior. I also have tried without the SD card and with the HDMI plugged in. According to the Pi official docs i should at least see a bootloader diagnostic screen - which i don't. So I am thinking maybe my EEPROM or something like that needs to be "rescued"?

I also downloaded the latest eeprom recovery image (https://github.com/raspberrypi/rpi-eeprom/releases) and used the PiImager to create both a USB and a SD version of a recovery. Tried to boot with both and same behavior - as soon as i plug in power it starts the 3long/3short pattern as if its failing immediately. I also burned a SD card from the "Misc utility->bootloader->SD Card Boot" option.

Deep deep in the docs i found the error fo 3L/3S green - "I2C error - Pi 4". Can anyone point me to reasons for this and/or potential resolutions - or did i somehow fry my board...

  • So I am thinking maybe my EEPROM or something like that needs to be "rescued"? that's what I would do - though if the pattern is the same regardless of the presence or absence of sd card, and it's a pattern that isn't documented - you may have trouble with a rescue flash - still, give it a go
    – Bravo
    Commented Dec 29, 2021 at 21:46

1 Answer 1


See Pi4 Boot Problems Sticky

There is nothing that matches, so maybe you need to recount. The documentation may be slightly out of date.

  • I eventually found a larger table in the official raspberry pi docs that indicates 3L/3S is "I2C error - Pi 4". But i've found nothing more about this error during boot up. I know what IC2 is and i assume that upon powering up the CPU isn't able to talk to another chip - or maybe its the other way around
    – DaveInPA
    Commented Dec 29, 2021 at 23:54
  • @DaveInPA Could you post the link. The Pi uses I²C to configure an expander chip which controls on board functions (including LEDs.) Unfortunately this is probably a hardware failure.
    – Milliways
    Commented Dec 30, 2021 at 0:01
  • raspberrypi.com/documentation/computers/…
    – DaveInPA
    Commented Dec 30, 2021 at 1:03

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