BrendanF
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Is this a new revision??

Sat Mar 29, 2014 3:22 pm

Ordered 6 more PI's for some family members and got them the other day. I was looking at the diodes on the bottom the of the board to see about removing the old D14 to correct a CEC problem, and noticed that it is still there but now is labeled D13. Is this a correction for the CEC problem so I don't have to desolder it, or was there some other change made? Production date on the board is 1406.
- Try not to argue with stupid people. They just bring you down to their level and then beat you with experience.

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jojopi
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Re: Is this a new revision??

Sat Mar 29, 2014 4:40 pm

D14 is the ESD protection diode pair for the HDMI CEC data line. It was found to confuse some devices if the Pi was connected but unpowered. Late revision 1 boards left the component unpopulated to work around the problem.

Revision 2 PCBs have the high side of D14 connected to 5V0 instead of 3V3, which is believed to fix the problem. So since late 2012 the component has been fitted again, in the same place.

D13 is the ESD protection diode pair for the right channel of the analogue audio port. It should be towards the opposite edge of the board from the HDMI port?

BrendanF
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Re: Is this a new revision??

Sat Mar 29, 2014 4:54 pm

Definitely some confusion here.. Now more then ever..

So on my original Pi the 3 diodes under the HDMI port are labeled d14, d15, d16. I removed d14 to correct the CEC problem (no AudioReturnChannel) I was having and it worked.

On the new boards I just received, they are labeled d13,d14,d15. I tested one of the boards and it currently does cause the CEC problem, so should I remove d13 as it is located in the same spot as my old d14 or should I remove d14 in it's new location.
- Try not to argue with stupid people. They just bring you down to their level and then beat you with experience.

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Burngate
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Re: Is this a new revision??

Sat Mar 29, 2014 6:25 pm

I've just had a look at my Rev. 1 & Rev. 2 boards; they both look the same in that area - D14-16 under the HDMI, with D12-13 under the audio jack,
so I can't help.

I don't suppose you could post a photo of the back of your new board?

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rpdom
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Re: Is this a new revision??

Sat Mar 29, 2014 6:34 pm

I've just bought a new Pi too. It has D13, D14 and D15 labelled under the HDMI socket.
[edit]
and D11 and D12 under the audio jack.

Do we need new schematics?

BrendanF
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Re: Is this a new revision??

Sat Mar 29, 2014 9:02 pm

Untitled.jpg
Untitled.jpg (45.77 KiB) Viewed 5534 times
Here is a picture of the 3 diodes.. As you can see their numbering has changed.
- Try not to argue with stupid people. They just bring you down to their level and then beat you with experience.

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rpdom
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Re: Is this a new revision??

Sat Mar 29, 2014 9:21 pm

I also noticed on this new Pi that the SD card slot was a much firmer fit than my older ones. If this is part of a redesign it is a good thing :)
[edit]
Yes, that picture matches the recent one I bought.

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jojopi
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Re: Is this a new revision??

Sun Mar 30, 2014 1:06 am

That picture is tiny! But it is definitely a new PCB, not just a silkscreen change. I want to see the other side too.

There is a lot more ground fill on the new bottom layer. There are far fewer vias visible, so there must be blind or buried vias for the first time. Perhaps the PCB has fewer total layers as a result? It certainly must be optimized for high volume production.

Some components have at least moved sides, or may have been changed completely.

The resistors and capacitors have been renumbered drastically, not just the diodes. That is a mistake. Normally you keep the component designations as stable as possible across revisions, precisely to avoid questions like this. Illogical or gappy numbering is much better than confusion over "which is D14".

My guess is that D13 serves as the new D14, but I also thought that the CEC problem was fixed long ago…

BrendanF
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Re: Is this a new revision??

Sun Mar 30, 2014 2:06 am

Yeah I would like to have a bigger more detailed picture to share but the attachments are limited to 64k... The original picture I cropped that from was like 1M in size, and then had to shrink it down even further to get it to fit.. There are a lot of changes on the other side too, L1 and L2 are not installed, and there is a new L9, r4 to the left of them..

The CEC is still very much a problem, but only when the Pi is left connected via HDMI and not powered.

Hopefully one of the mods can shed some light on this.

I even checked the board revision with some command (I forget what it was) and it came back with 000E.
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Paul Webster
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Re: Is this a new revision??

Sun Mar 30, 2014 6:17 am

Looks like this thread needs an official commentator - especially if the function of named / numbered items has changed.

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rpdom
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Re: Is this a new revision??

Sun Mar 30, 2014 6:53 am

Also, what was the polyfuse called F3 is now F1 (as the old F1 and F2 were removed from the design). The overvolt protection diode is now D16 instead of D17. Most of the resistors and capacitors have changed number, but the connector numbering is the same and importantly the test points are the same (no point in changing those.

I can probably upload some large pics with links later, if there is demand for them.
[edit]
Ok, taken pics, lets see if I can link to them...

Underside:
Image
(full picture 1600x1200 at http://pics.rpdom.net/l?hMj4lG)

Top side:
Image
(full picture http://pics.rpdom.net/l?rpgX7h)

gsh
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Re: Is this a new revision??

Sun Mar 30, 2014 8:13 am

Light...

Yes it's a slightly tweaked version of the rev 2 PCB. Sometimes we make small changes to modify small things (for manufacturing reasons generally). We wouldn't have changed component numbers had we had a choice unfortunately we didn't and they got changed. I'll have a chat with people about releasing a new version of the schematics to cover the component renumbering

Thanks

Gordon
--
Gordon Hollingworth PhD
Raspberry Pi - Director of Software Engineering

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Burngate
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Re: Is this a new revision??

Sun Mar 30, 2014 10:54 am

rpdom wrote:... but the connector numbering is the same and importantly the test points are the same (no point in changing those.
The numbers of some have changed
P1 => P1 fortunately - main GPIO
P2 => P3
P3 => P4
P5 => P6 - extension GPIO
P6 => P2 - reset

PS Thanks for the pics

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jojopi
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Re: Is this a new revision??

Sun Mar 30, 2014 11:08 am

The vias have reappeared in the high resolution photos, so not the major redesign I thought. There is still a lot more copper fill on both sides, and some surprising changes.

L1 and L2 near the HDMI are now unpopulated. In the previous revisions, components in the same place and with the same designations were in series with the DDC signals, so could not have been omitted.

There appear to be more passives in total around the 9512, and I am particularly intrigued by the new R41/42 in the northeast corner, which are both unpopulated and nowhere near any signals.

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rpdom
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Re: Is this a new revision??

Sun Mar 30, 2014 11:48 am

Burngate wrote:
rpdom wrote:... but the connector numbering is the same and importantly the test points are the same (no point in changing those.
The numbers of some have changed
P1 => P1 fortunately - main GPIO
P2 => P3
P3 => P4
P5 => P6 - extension GPIO
P6 => P2 - reset
I checked P1 and missed the fact that P5 is now P6 :oops: I did check the USB, net, video connectors though an made sure they were in the same positions.
PS Thanks for the pics
No problem :)

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Burngate
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Re: Is this a new revision??

Sun Mar 30, 2014 4:26 pm

As an aside, since P4 was non-existant, and now P5 isn't there, does any-one know what it wasn't used for?
I can understand renumbering real things, but renumbering imaginary things ...

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rpdom
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Re: Is this a new revision??

Sun Mar 30, 2014 4:45 pm

P4 was the network connection. The label is hidden under the socket, but I can see it on my model A.

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FTrevorGowen
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Re: Is this a new revision??

Sun Mar 30, 2014 7:19 pm

rpdom wrote:P4 was the network connection. The label is hidden under the socket, but I can see it on my model A.
And, FWIW, visible (just about**) on my model A photo' here:
http://www.cpmspectrepi.webspace.virgin ... RasPi.html
Trev.
** Partially obscured by the Pimoroni "Pibow" case's "camera symbol".
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

garlad
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Re: Is this a new revision??

Mon Jun 23, 2014 1:32 pm

"On the new boards I just received, they are labeled d13,d14,d15. I tested one of the boards and it currently does cause the CEC problem, so should I remove d13 as it is located in the same spot as my old d14 or should I remove d14 in it's new location."

Hi, I'm in the same boat.
Removed D14 off my first Pi which solved the CEC issue on my Sony Bravia.
Bought another pi, but this one has d13, d14, d15 as above.
Should I now remove d13 off this one?

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AndrewS
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Re: Is this a new revision??

Mon Jun 23, 2014 5:13 pm

I know nothing about CEC, but some of the questions in this thread may be solved by http://www.raspberrypi.org/documentatio ... ematics.md

garlad
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Re: Is this a new revision??

Tue Jun 24, 2014 9:26 am

AndrewS wrote:I know nothing about CEC, but some of the questions in this thread may be solved by http://www.raspberrypi.org/documentatio ... ematics.md
I wish I knew what to look for

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