“New” Raspberry Pi 3B v1.2/v1.3 May be Incompatible with Cases with Embedded Heatsink

As we’ve recently seen with Raspberry Pi 4 v1.2, the Raspberry Pi Foundation will sometimes provide new revisions of their boards with small differences or fixes that most users won’t notice, so they will not make announcements about those minor revisions.

Somebody on the RPi forums noted there may be a “new version of Raspberry Pi 3B“, and the discussion points out there are actually two such revisions that are mass-produced from various companies.

It turns out the Foundation also posted PCN (Product Change Notices) on the product page of their boards, so we can know exactly what has changed and when.

The fist PCN for v1.2 board is dated November 1, 2018, and explains the SoC has changed switching from BCM2837 to BCM2837B0 found in Raspberry Pi 3B+ but with frequency limited to 1.2 GHz.

The PCN further explains the timing of the change:

The new part will be phased into manufacturing from January 2019 in both China and UK factories. There will be a transition period where both old and new units are available in the distribution channel.

The second PCN – 19th December 19, 2019 – states the change will impact all Raspberry Pi 3B boards, including the ones manufactured in Japan. Note that when Raspberry Pi 3B launch in 2016 the PCB was already revision v1.2, so there are no changes to the PCB itself.

I suspect the change will only affect a few people, since sales of Raspberry Pi 3B boards have likely plummeted, and the board will be the same except for one point:

New part, BCM2837RIFSBTB0T has a Z height which is 1.06mm higher than the original part, BCM2837RIFBGT.

That means if you have one of those metal cases designed with an extrusion to cool the processor on the original Raspberry Pi 3B board and buy a new Raspberry Pi 3B it may not fit in the case. Other than that, there should be no differences, and the software is the same.

What about Raspberry Pi 3B v1.3 you may ask… I just don’t know since I haven’t been able to find details, but I suspect BCM2837 processor is not mass-produced anymore and must be using BCM2837B0 like v1.2, plus some other undocumented changes.

Thanks to RaspberryParaTorpes for the tip.

Support CNX Software - Donate via PayPal or become a Patron on Patreon
Subscribe
Notify of
guest
10 Comments
oldest
newest most voted
Willy
Willy
3 months ago

One solution might be to delid the SoC. It happened to me by accident on the RK3288 of a MiQi board when trying to remove a heatsink that I pasted with silicon glue. The silicon glue was stronger than the glue used to keep the lid on the SoC. And under it, it’s just the plain flat plastic, the silicon is not accessible as it’s inside the plastic.

theguyuk
theguyuk
3 months ago

@Willy so if plastic underneath do the lids actually provide any significant cooling?

Willy
Willy
3 months ago

No idea. I suspect it only helps smoothing the heat on the whole surface by using a lower thermal resistance material.

wenming
3 months ago

any news about CM4?

rooted
rooted
3 months ago

What is a CM4?

tkaiser
tkaiser
3 months ago

> That means if you have one of those metal cases designed with an extrusion to cool the processor on the original Raspberry Pi 3B board and buy a new Raspberry Pi 3B it may not fit in the case More likely you just need a thinner thermal pad or a copper shim or just some thermal paste and those metal cases become way more efficient since I’ve seen not a single such case with a distance between SoC and cooler of less than 1 mm. I’m always using a small piece of Blu Tack to determine the distance between… Read more »

AntonSchroeder
AntonSchroeder
3 months ago

No way 🙂 I thought we were the only company using Blu Tack for cooler interface testing!

manuti
3 months ago

For me, the change is more or less irrelevant. But, the forum post is another display of fanboys defensive way to answer an innocent question.

manuti
3 months ago

Grand merci. Good review about the situation and another issue to show the way Raspberry Pi foundation “inform” his clients and users.

Advertisements