C6100 extender board USB

dba

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Nice find Chuckleb - USB traces on the c6100 motherboard! If the pins are in order then the solder point encircled in white will be ground. The others, in order moving away from ground, are signal positive, signal negative, and +5V. Who is brave enough to give it a try?

Update: Or of course it could be the reverse of the above - TheBay below says the circled is +5V and he seems to know what he's talking about. Easy enough to test.

I was wondering if anyone has figured out how to enable the USB port on the extender, if that is even possible.



That, combined with a tiny USB key would be nice.
 
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TheBay

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Nice find Chuckleb - USB traces on the c6100 motherboard! The solder point encircled in white will be ground. The others, in order moving away from ground, are signal positive, signal negative, and +5V. Who is brave enough to give it a try?
If I had a c6100 to play with I'd have it done and do a write up :(

Looks like 2 ceramic capacitors are required and next to it looks like a 4pin DOM power header, which could also be utilised.

The solder point circled (squared) is +5v btw.

I have all the kit here to do such things as I run an electronics technology company.

Stop tempting me to buy a c6100:D

*EDIT*
@dba, +5v won't be there at that pin without the capacitors, it should read +5v before the caps, if it does read +5v at the USB pin the caps are just for filtering, if not they are there for protection/filtering/current surge for hotswap of USB.

Also values will need to be found for the capacitors, if I'm not mistaken isn't the C6100 based on a Supermicro board?
 
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Chuckleb

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I think the first generation of the C6100 was OEM'd to Supermicro, so this definitely could be based off that design. I have an AMD cluster at work that is the twin-twin setup, I could pull one of those boards and see if it has a usb plug inside (never bothered to look).

I think a lot of us would love to have you figure this out ;) I have a spare board so would be glad to give it a try but I think there are a few pieces that I are missing that I don't know other than the USB plug.

I assume that the USB data passes back over the FP connector bundle above it? I didn't see any other connections between main board and the expander.
 

TheBay

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I think the first generation of the C6100 was OEM'd to Supermicro, so this definitely could be based off that design. I have an AMD cluster at work that is the twin-twin setup, I could pull one of those boards and see if it has a usb plug inside (never bothered to look).

I think a lot of us would love to have you figure this out ;) I have a spare board so would be glad to give it a try but I think there are a few pieces that I are missing that I don't know other than the USB plug.

I assume that the USB data passes back over the FP connector bundle above it? I didn't see any other connections between main board and the expander.
It's a multilayer PCB so you may not see the two data tracks, it probably goes straight to the chipset or hub IC, Is there any way to view that part of the board when its in the chassis? 5 minutes with a multi meter and an oscilloscope will tell you everything, even a multi meter will crudely give you an idea if the data line is present if very careful :).

If anyone in the UK/Europe has one I could do some work
 

s0lid

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Nice find Chuckleb - USB traces on the c6100 motherboard! If the pins are in order then the solder point encircled in white will be ground. The others, in order moving away from ground, are signal positive, signal negative, and +5V. Who is brave enough to give it a try?

Update: Or of course it could be the reverse of the above - TheBay below says the circled is +5V and he seems to know what he's talking about. Easy enough to test.
Cicrled is +5V most certainly as the as the usb connectors shield is grounded. But it's possible that there's no actual connection between interposer and motherboard.


Also it's possible that that USB port is only connected to connector J13 (silkscreen on the interposer, no actual connector installed)
 

TheBay

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If anyone has a multi meter its easy to find out, or I can do the same if I have a board to pay with. I could fit the components and send it back to someone to test. J13 is more than likely a header not an input as it too requires power via the capacitors, the trace goes elsewhere. Not between J13 and USB. The USB signal will be via the PCB gold fingers or "FB Con"
 
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dba

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I have a spare complete motherboard and can donate and ship the interposer for an experiment. It sounds like we just need to figure out the capacitor design first?

If anyone has a multi meter its easy to find out, or I can do the same if I have a board to pay with. I could fit the components and send it back to someone to test. J13 is more than likely a header not an input as it too requires power via the capacitors, the trace goes elsewhere. Not between J13 and USB. The USB signal will be via the PCB gold fingers or "FB Con"
 

TheBay

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I have a spare complete motherboard and can donate and ship the interposer for an experiment. It sounds like we just need to figure out the capacitor design first?
Yeah that sounds like an idea, initially all I would need is the interposer, would be great if someone in the UK/EU could send one, I'll probe it out and see where the data lines go. Then they can test it (won't cause any damage) I can just put any USB socket on it for testing, the proper ones will need to be ordered in bulk or will cost stupid prices for a single item + shipping from my supplier.

A few ways to find out the capacitance:
1: Find an original interposer with USB and check the ESR of the caps off the board (Ceramic SMD of that size won't be labled)
2: Contact Dell/Supermicro, I can do this
3: Look at other board designs as it's only the +5V and nearly all motherboards with SMD's on that line for USB will be around the same rating, provided the board supplies a stable true +5V. I can check some X9SC** boards as they have an internal USB header.

*EDIT*
This makes sense to me:

http://www.google.co.uk/url?sa=t&rc...zElJ5QzuQeGSbEDrA&sig2=oDctnbYrlYdrvfMOmfSF0w

Going from here, it could be a DIY job or if there is enough interest and it works I can order the USB sockets and Caps in bulk and do it on an exchange basis at a cost + shipping etc, as long as I can get my hands on a few interposers the turn around would be quick.
 
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Chuckleb

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I traced everything on the board that I could and I identified the full path for the 5V. The data lines seem to only go to J13 so it is probably a header that will require a cable back to the motherboard. Based on that assumption, I searched through the whole motherboard and the manuals and found one thing that could be interesting.

There is a connector near the SATA ports that is unlabeled in the manual (left of #13 on page 129). I have a picture of it here.




Also noticed that in Dell C6105 board manual, there is a connector in the same area marked as internal USB..http://www.manualslib.com/manual/254665/Dell-Poweredge-C6105.html?page=147#manual
 
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Tsmooth3

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I like the SATADOM idea, so I looked for a USB port or header on the motherboard - there isn't one.
What about the "usb key" box on the interposer board? There's also an 8-pin connector hidden under the pci-e riser labeled USB.

And does anyone know what the white 4-pin IPMB connector between CPU0 and memory DIMMs is for? Could power possibly be drawn from there?









I've been trying to follow along, so sorry if this was already discussed and I missed it.
 

TheBay

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I think you would want to ping a seller and get one shipped out w/ a custom shipping quote.
Good idea, I only need a rat of one with one board, no drive bays etc. Seeing as they are so popular I think I can work some magic with these, hardware and bios level.
 

dba

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Good find. Is the interposer connector a Red Herring then? Do we need to focus on getting a cable to adapt the motherboard 8-pin connector to one or two USB ports?

That's one well hidden connector, by the way.


What about the "usb key" box on the interposer board? There's also an 8-pin connector hidden under the pci-e riser labeled USB.

And does anyone know what the white 4-pin IPMB connector between CPU0 and memory DIMMs is for? Could power possibly be drawn from there?









I've been trying to follow along, so sorry if this was already discussed and I missed it.
 
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Chuckleb

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Tsmooth:

So far what I've found is that the USB on the interposer isn't connected to anything on the main board, it looks like it would connect to a set of headers and then a cable would pass over to the motherboard. It could theoretically go all they way back to the USB connector near the SATA ports. The IPMB seems to be a motherboard connector to connect to the BMC and communicate with it.

TheBay:
I traced the 5V from the supply through to the C1 and C2 and then to the USB connector and back. The FP connector doesn't offer any communication to the USB data, nor do the golden fingers. It seems that most of the finger connectors are for the SATA and the FP status.

I feel that there is something with the 8pin picoblade connector on the board. Pins 1+8 seem to be 5V supply and the rest all ground out and give me a full 5V reading. I don't have any picoblade connectors handy but will probably order an 8pin for testing. I had a 2pin and tried to play with it a little but got nowhere.

This should be the picoblade conector
Pre-crimped cables

Annoyed by the $10 shipping... but if don't find some at work tomorrow, will probably order a set and see what I can get working.

On a positive note, you can definitely pull 5V from the 8pin picoblade of the mainboard without having to splice something.

** Edit **
Bah, ordered parts so unless someone else figures it out first, will update this weekend. :)
 
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s0lid

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Had a quick look, that usb connector under pci-e slot seems like good start.
1. It has 2 usb's
2. It's missing decoupling capacitors, 0.1-10uF should do it. Yes you'll need to get soldering.
3. usb connector pads in interposer are directly connected to j13, caps c1 and c2 are not electrically connected.

I'll have another look when i get 3rd node for hacking :p
 
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