[Solved] Recent Pi 3B+ Unable to boot Raspbian Stretch

[dfinegan]

Hello, I have a pi/picamera based device that is in use by several customers. This device was developed a few years ago using Raspbian Stretch. While testing some recently received new 3B+ units (received Sept 2023), I have found that none of them boot up using the SD card that is being used on older units. On power up, the red LED turns on and the green LED flashes a repeating pattern: 4 slow. 7 fast flashes. Nothing appears on the display.
I have done some digging to find the meaning of the flash code. The closest that I can find is an indication of "Power Failure Type B". However, this code is associated with the Pi 4, not the Pi 3. I have found no reference to this code with a Pi 3B+.
I created a new Stretch SD card without any of my code and saw the same flash code.
I can get the Pi to boot up by creating a new Raspberry Pi Buster SD card. So the idea of a power issue appears unlikely.
Unfortunately, the code I currently have for my product fails to run under Buster. I haven't given up on that yet, but a combination of the new picamera handling and the newer OpenCV library implies I have a good deal of rebuilding ahead of me.

So. On to my questions:
Has anyone else experienced this?
What may have changed in the Pi 3B+ hardware that would prevent Raspbian Stretch from running?
Is there any way to identify a Pi 3B+ board that will or will not run Stretch? Thus far I can see no differences.

Thanks for any constructive feedback. I look forward to seeing your ideas.

[BigRedMailbox]

I may be in a similar situation. Where you want/need to boot up an older version of Raspian on a newer computer.

I think (but have not been able to test yet) that you should just be able to copy the /boot partition from a newer version onto the /boot partition of the old one and it should "just work".

[rpdom]

I may be in a similar situation. Where you want/need to boot up an older version of Raspian on a newer computer.

I think (but have not been able to test yet) that you should just be able to copy the /boot partition from a newer version onto the /boot partition of the old one and it should "just work".

Don't copy the config.txt or cmdline.txt if you want the system to boot correctly.
You probably don't need to copy the kernel*.elf files, and if you do you will get problems with module mismatches.

What you probably need to do is to update the firmware files: fixup*.dat and start*.elf, and possibly bootcode.bin.
I've got Raspbian Wheezy running on a Pi 4B.

[dfinegan]

Thank you both for the quick and interesting responses. I am in the process of creating a fresh target SD card with Stretch and I will get right to corrupting it and let you know how it turns out.

[6by9]

https://pip.raspberrypi.com/categories/ ... -9-PCN.pdf

Reason for Change
Move to a new power management chip.
...
Software/Firmware Changes Required
This new product revision is supported in firmware versions from September 2021 onwards.

Whitepaper on updating the firmware - https://pip.raspberrypi.com/categories/ ... rmware.pdf

[dfinegan]

Perfect! That is exactly what I was looking for and it worked great.
Thanks for help!

[mjdieter]

Just got a new Pi3b+ primarily because I wanted to use my existing SD cards and systems that have been developed over years. I couldn't get it to boot on the older SD card systems with a 4 long and 7 short flash led code. I searched for most of a day until I found this post. Thanks to those who answered. Replacing the fixup*.dat and start*.elf files my old SD card with the new one listed in the documentation did the trick! Thanks again!

[Meaco]

Hi, can I add to this confusing scenario.

I recently got 50 new Pi 3 B+ boards for an application,and none will boot up using an SD card that works in an older 3B, 3B+ and a Pi4, the SD card is running the most up to version of Buster. As soon as I put the SD card into the newer 3B+ I get the 4 long and 7 short dashes. Corrupt start.elf file. I can put the card back into the older 3B+ and it boots up fine. I've updated the OS, I've tried updating the boot folder and following the instructions on the white paper. Same result every time. I've even updated the OS to Bullseye then on to Bookworm and no change. A new install of Bookworm runs but I don't really want to have reimage and reinstallsoftware on 50 SD cards .
Any hints or tips would be very helpful and time saving! Thanks.

[6by9]

Hi, can I add to this confusing scenario.

I recently got 50 new Pi 3 B+ boards for an application,and none will boot up using an SD card that works in an older 3B, 3B+ and a Pi4, the SD card is running the most up to version of Buster. As soon as I put the SD card into the newer 3B+ I get the 4 long and 7 short dashes. Corrupt start.elf file. I can put the card back into the older 3B+ and it boots up fine. I've updated the OS, I've tried updating the boot folder and following the instructions on the white paper. Same result every time. I've even updated the OS to Bullseye then on to Bookworm and no change. A new install of Bookworm runs but I don't really want to have reimage and reinstallsoftware on 50 SD cards .
Any hints or tips would be very helpful and time saving! Thanks.

viewtopic.php?p=2143327#p2143327

[BigRedMailbox]

Any hints or tips would be very helpful and time saving! Thanks.
viewtopic.php?p=2143327#p2143327

It sounds like OP followed the instructions but it still didn't work. Hence, his posting to this thread.

Are you saying there is more to it than just what has been discussed so far? Are you saying that the "white paper" covers more than has already been mentioned here?

[6by9]

Any hints or tips would be very helpful and time saving! Thanks.
viewtopic.php?p=2143327#p2143327

It sounds like OP followed the instructions but it still didn't work. Hence, his posting to this thread.

Are you saying there is more to it than just what has been discussed so far? Are you saying that the "white paper" covers more than has already been mentioned here?

The PCN states "This new product revision is supported in firmware versions from September 2021 onwards".

Raspberry Pi OS Buster became the Legacy release over 2 years ago, and only gets upstream Debian updates. It is highly likely that the firmware is too old.
An up to date Bullseye would have expected to work, but without details of which versions Meaco (not the original poster in this thread) is actually seeing it's impossible to say exactly what they are running.
Updating the OS between revisions has never been recommended, so no guarantees over what is going on or what versions they have installed.

The white paper covers updating the firmware files from https://github.com/raspberrypi/firmware ... stable.zip, which is what is required in this situation.

[BigRedMailbox]

So, the answer is "yes".

[6by9]

So, the answer is "yes".

1 answer to 2 questions??!

Is posting a link to the white paper not guidance to actually read it, and I would say that is therefore part of the discussion so far.

Both dfinegan (as the OP) and mjdieter appear to have been able to follow that part of the discussion. Meaco appears to have ignored it, but not actually said what instructions he has followed.

Why are we even discussing this?

[davidcoton]

Why are we even discussing this?

Because, the problem is that:

... I've tried ... following the instructions on the white paper.

So something else seems to be getting in the way, not just the issues addressed so far.
It is possible (probable?) that the instructions were incompletely followed, but some further diagnosis seems necessary.

[rpdom]

Is there a possibility that your Stretch card could have been created with the old NOOBS system? If so, the upgrade is a bit more complicated.

It might be easier to convert the card to a Non-NOOBS setup if that is the case.