RPi B+ won't boot, older B+ boots fine

[marakalastic]

Hey guys,

I've read through the Boot Problem sticky already and none of the issues mentioned in that post is similar to my situation.

I have an image that I have been writing to micro SD's for my B+'s. I have had no issues with this until the latest batch of B+'s that I ordered from Adafruit. I've tested 5 that I purchased from Adafruit and none of them can read the micro SD. Putting this same micro SD into an older B+ and it boots fine (green LED flashes).

I've noticed that this new batch of B+'s has black display and camera headers while the older B+'s have white display and camera headers. Are there more subtle changes that have been done to the B+ that I am unaware of?

I've kept the PSU and micro SD the exact same for my tests. It is to my understanding that this new batch of B+'s must be different than previous B+'s since it cannot boot while the old ones can. What are the chances an entire batch of RPi's from Adafruit are bad?

[davidcoton]

Have you tried a newly downloaded image? I'm not aware of any changes that should affect B+ booting, but it's always worth knowing what the extent of the problem is, in order to determine the solution.

I would think it is highly unlikely (but not impossible) for a whole batch of boards to be faulty, unless someone accidentally shipped a box full of test rejects.

[marakalastic]

I just tried a newly downloaded image (a Fedora minimal) and it successfully reads on both B+'s.

This means that the 2 B+'s I have are NOT identical. Even if there was a problem with my image, it would have to produce the same result if the boards were truly identical, no?

[davidcoton]

Was the older image also Fedora minimal? (This may turnout to be irrelevant, but let's get the full picture.)

There have been no advertised changes to the B+, as far as I know. A firmware change is unlikely, since it is contained in ROM on the SOC. It is possible there has been a change to the factory coding of OTP memory (either deliberate or accidental), that could break older images. RPF/RPT would need to confirm or deny that.

The other possibility is a hardware change. Are you sure the boards are all B+? Read the board silkscreen closely -- are they all the same revision? Where are they labelled as being made? Apart from connector colours, are there any obvious changes to component layout? Remember that the B+, 2B and 3B are all similar, but older code won't boot on newer boards.

[rpdom]

It is quite possible that the newer boards are using a different memory chip that isn't supported by the old bootcode.bin file.

First, have a look at the brand name on the memory chip. On the B+ it is mounted on top of the main SoC on the board. I think newer boards are using Elpida memory, while older ones may use Samsung or another brand.

Try copying the bootcode.bin from a new card onto the old card and see if it boots.

[marakalastic]

UPDATE: I just tested the newest version of Pidora (R3) and it does not boot on the newer B+'s. Seems the Raspberry Pi Foundation has made Pidora completely incompatible with the Elpida chipset.

Was the older image also Fedora minimal? (This may turnout to be irrelevant, but let's get the full picture.)

There have been no advertised changes to the B+, as far as I know. A firmware change is unlikely, since it is contained in ROM on the SOC. It is possible there has been a change to the factory coding of OTP memory (either deliberate or accidental), that could break older images. RPF/RPT would need to confirm or deny that.

The other possibility is a hardware change. Are you sure the boards are all B+? Read the board silkscreen closely -- are they all the same revision? Where are they labelled as being made? Apart from connector colours, are there any obvious changes to component layout? Remember that the B+, 2B and 3B are all similar, but older code won't boot on newer boards.

The older image I have is a Pidora ( 20, released 2014) while the Fedora minimal I tried is 25.

Yep, both new boards and my old ones have "Raspberry Pi Model B+ V1.2" and "Raspberry Pi 2014" under it. Both are labelled as being made in the UK. I briefly looked at both boards to compare differences but nothing seems obviously different. After what rpdom pointed out though, I did find a big difference that could be the root of the problem.

It is quite possible that the newer boards are using a different memory chip that isn't supported by the old bootcode.bin file.

First, have a look at the brand name on the memory chip. On the B+ it is mounted on top of the main SoC on the board. I think newer boards are using Elpida memory, while older ones may use Samsung or another brand.

Try copying the bootcode.bin from a new card onto the old card and see if it boots.

I've actually just looked at the old one and that memory chip is made by Micron while the newer board is Elpida. Why wasn't this big of a change a huge deal if it breaks older (2014) images?

I've tried copying the bootcode.bin over and that results in 1 green blink. Obviously, my micro SD isn't actually corrupt, more likely is that the bootcode.bin for Fedora minimal 25 isn't appropriate for Pidora 20.

I'm not really sure what my options are at this point, is it possible to generate a new bootcode.bin for Pidora 20 that will work with the new memory chip? Or would I have to migrate over to a newer version of Pidora because of a hardware change that was made?

[davidcoton]

The change in memory manufacturer is almost certainly the culprit.

I don't know much anything about the differences in bootcode.bin for different OSs, if you can find a more recent Pidora image I would try the bootcode.bin from that with the older build. Otherwise you might be into generating a new build of your distribution. The good news is that new S/W should work with old and new H/W.

[marakalastic]

The change in memory manufacturer is almost certainly the culprit.

I don't know much anything about the differences in bootcode.bin for different OSs, if you can find a more recent Pidora image I would try the bootcode.bin from that with the older build. Otherwise you might be into generating a new build of your distribution. The good news is that new S/W should work with old and new H/W.

I just tried to boot with the newest Pidora image I could find (still 2014 though) but no luck. Looks like generating a new build is the only solution for me.

The help is much appreciated. Didn't think that they would make such a software breaking change (unless the amount of people using Pidora is negligible to them).

[rpdom]

The change in memory manufacturer is almost certainly the culprit.

I don't know much anything about the differences in bootcode.bin for different OSs, if you can find a more recent Pidora image I would try the bootcode.bin from that with the older build. Otherwise you might be into generating a new build of your distribution. The good news is that new S/W should work with old and new H/W.

I just tried to boot with the newest Pidora image I could find (still 2014 though) but no luck. Looks like generating a new build is the only solution for me.

The help is much appreciated. Didn't think that they would make such a software breaking change (unless the amount of people using Pidora is negligible to them).

Copy the bootcode.bin from the latest Raspbian image (Raspbian Lite is smaller to download). It should be sufficient to just update the bootcode.bin. It sounds like whoever packages the Pidora images hasn't used the latest code.

[marakalastic]

The change in memory manufacturer is almost certainly the culprit.

I don't know much anything about the differences in bootcode.bin for different OSs, if you can find a more recent Pidora image I would try the bootcode.bin from that with the older build. Otherwise you might be into generating a new build of your distribution. The good news is that new S/W should work with old and new H/W.

I just tried to boot with the newest Pidora image I could find (still 2014 though) but no luck. Looks like generating a new build is the only solution for me.

The help is much appreciated. Didn't think that they would make such a software breaking change (unless the amount of people using Pidora is negligible to them).

Copy the bootcode.bin from the latest Raspbian image (Raspbian Lite is smaller to download). It should be sufficient to just update the bootcode.bin. It sounds like whoever packages the Pidora images hasn't used the latest code.

Did just that. It will still only boot on the older B+ and not the newer one. It will attempt to read my image with the new bootcode.bin as shown with a single green LED blink but then no activity occurs after.