Adding missing SATA connectors to motherboard

I have some motherboards designed for 4-6 SATA ports, but only 2 SATA connectors were installed, and I'd like to add the missing connectors plus any needed termination resistors. Here's an example with an ECS GeForce 6100SM-M v. 1.0 motherboard:

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What are the values of the missing resistors? I thought that each pair of SATA data lines needed one 100 ohm resistor between them, but on this circuit board the resistors seem to be arranged differently.

Reply to
larry moe 'n curly
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You're assuming that the second SATA controller exists to utilize them.

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Conor

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Reply to
Conor

Even if a chip is in place that has unused ports on it, the MOBO BIOS will not carry them.

Reply to
Archimedes' Lever

Yes, and apparently the NVidia chipset does support additional SATA devices. I don't know if the BIOS does, and it's possible that a termination voltage source/sink isn't there fro the extra SATA connectors.

Reply to
larry moe 'n curly

Hours??? Similar mods in the past took me 20 minutes, including the time to desolder the parts from a junked mobo.

That would entail a 500' walk to Fry's Electronics.

If I got paid that much, I'd also take hours to do this job. ;)

I don't see any problem except possibly an active termination voltage regulator, but because differential signals are involved, I assume that only ordinary resistors are used.

Just curious: How many times have you done mods like this?

Reply to
larry moe 'n curly

On Sat, 10 Jan 2009 06:57:06 -0800 (PST), "larry moe 'n curly" put finger to keyboard and composed:

The "resistors" at the SATA4 connector appear to be labelled as C151-4. This begs the question, what are caps doing on a high speed interface?

This URL talks about 100 ohm termination resistors across the two signal pairs:

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This URL suggests that 20K pullup and pulldown resistors may sometimes be used in noisy environments:

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- Franc Zabkar

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Reply to
Franc Zabkar

On Sat, 10 Jan 2009 09:52:10 -0800 (PST), "larry moe 'n curly" put finger to keyboard and composed:

There exist utilities (eg AMIBCP) that can enable hidden features in your BIOS. It could be that your additional SATA ports are supported, but they may have been turned off by default.

For example, count the "not active" features in this AMI BIOS:

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- Franc Zabkar

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Reply to
Franc Zabkar

He's obviously never done this kind of thing so the hours are needed to assemble the tools and practice. It wouldn't be especially hard to solder given practice with similar work, would be harder to find an incompatible SATA header than an compatible one, and indeed is a 20 minute job if the board's not already in a fully assembled system.

Uphill both ways!

LOL

The resistors you could probably just measure, since they're present for the other two ports. "IF" all other elements of doing this were in place, at most the bios would have the feature hidden but still present logically if the capability were otherwise present.

Are nVidia 430 and 410 pin-compatible, at least enough that ECS did what they do best, economized by using the same PCB layout for either possibility? That seems to be the problem, use of 410 chipset which only supports 2 SATA ports instead of 430 chipset which supports 4. Unless nVidia is pulling a fast one and 410 is just a whole 430 chip rebranded that manufacturers have agreed not to implement all 4 SATA ports on, it seems having the 410 is the show-stopper.

Reply to
kony

I could find a reference to AC or DC coupling here. (I bet some sata-io.org document would cover this in more detail.)

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I have an Intel sample schematic where the 1.5Gb/sec SATA interface was DC coupled. And can also find examples with AC coupling.

Pg. 8 here uses 10nF capacitors.

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PCI Express uses AC coupling, and also uses 8B10B coding like SATA does. At least with PCI Express, coupling caps are used consistently.

Paul

Reply to
Paul

Hello, I am not an expert, but the caps you see are the coupling caps. The termination resistor would be at the end of the line, not the middle. I'm not sure what the value of the cap would be, but 100nF is a good start. I could be wildly wrong about the value, I know nothing of the SATA specs.

Reply to
a7yvm109gf5d1

On Sat, 10 Jan 2009 19:19:29 -0500, Paul put finger to keyboard and composed:

Thanks again. I'd always thought AC coupling wasn't necessary when the two devices at either end of the cable were differentially coupled or powered from the same supply. I tend to associate AC coupling with analogue circuits rather than digital.

- Franc Zabkar

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Reply to
Franc Zabkar

Are the data sheets online ?

Graham

Reply to
Eeyore

Checking out the existing components used in those locations would be helpful. Can the OP read the markings on them ?

And I bet an application note or two might come in handy too.

As elsewhere mentioned, the BIOS setup may be the most tricky stumbling block, but there are people around who know how to mod them.

Graham

Reply to
Eeyore

Which chipsets do these boards have? AFAIK, nVidia 400,

405, 410 only support 2 SATA. 430 supports 4.

One thing we might need to consider is that if anyone were to pull some stunt trying to save a fraction of a cent on resistors, it'd be ECS/PCChips.

I don't have an nForce /4xx series board available to check it, but checking an old A7N8X board that uses a Silicon Image SATA controller, it has the SATA data pins coupled directly to the chip inputs with a 2200pF ceramic chip capacitor in series.

The picture linked above is a little high in contrast so it's hard to tell but might those empty spots be corresponding to capacitors on the adjacent used SATA spots? Further, if you can trace these data lines to the chipset, are there unused surface mount pads adjacent to it?

Reply to
kony

I must be blind, upon looking at the picture again obviously what I was thinking of is supposed to be capacitors as marked with the C(nnn) silkscreening but now I wonder if you were looking at the resistor, R(nn) silkscreened positions above the SATA port in the pictures. They don't seem to be for SATA?

Reply to
kony

I live in Phoenix. What do you mean by "hill"? ;)

This mobo has an nVidia 405 chipset. :( You've made the case for me to give up on this project.

Reply to
larry moe 'n curly

You're obviously an idiot.

Multi-layer boards *are* difficult to work with. Try removing through hole devices on an 0.092" thick PCB. I can certainly do simple SMD work. I have both laid down more fresh lead as well as reworked more assemblies than you probably ever will. I was working on electronic assemblies back in the seventies. You know... before you were even born, punk.

I know more about soldering and connections between metals than you ever will.

Now this 'kony' retard is talking about rework and post fit operations in an *installed system*, and he claims that *I* don't have any experience.

Bwuahahahahahahahahahahahahaha!

Reply to
Archimedes' Lever

The slight incline that the flood rushes down toward you on.

Reply to
Archimedes' Lever

I let my technicians do that work for me.

My technicians can do very complicated SMD work.

Sounds like you were an assembler before being a technician?

I let my technicians worry about good solder joints.

I think you have lots of technician level experience, based upon your comments here. In our company a technician with an attitudde like your would not last very long though. Only the very best engineers can have an attitude, in my experience.

pretty cocky for being a technician.

Reply to
bulegoge

Jolly Good for you. I doubt you know much else.

Graham

Reply to
Eeyore

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