SATA data cable - pin query

Hi,

Further to the issues I have been having with a broken SATA data
connector (which still works after being wedged on!) I was wondering
about the pin arrangement on the connector. I note there are 2
transmit and 2 receive pins with 3 ground pins...

My question is - what if one or more of the ground pins were not
connected, would the drive still work and if so is it dangerous? i.e.
must ALL 7 pins be connected before the drive will work/be seen by XP?

thanks for your help :D

Gav

gavin@my-deja.com wrote:

> Further to the issues I have been having with a broken SATA
> data connector (which still works after being wedged on!)
> I was wondering about the pin arrangement on the
> connector. I note there are 2 transmit and 2 receive pins

Each pair is a balanced pair, like with a twisted pair in a cable.

> with 3 ground pins...

> My question is - what if one or more of the ground
> pins were not connected, would the drive still work

Yes.

> and if so is it dangerous?

Nope.

> i.e. must ALL 7 pins be connected before the drive will work/be seen by XP?

The 4 data lines are crucial, not all the ground lines are.

Rod Speed wrote:
> gavin@my-deja.com wrote:
>
>> Further to the issues I have been having with a broken SATA
>> data connector (which still works after being wedged on!)
>> I was wondering about the pin arrangement on the
>> connector. I note there are 2 transmit and 2 receive pins
>
> Each pair is a balanced pair, like with a twisted pair in a cable.
>
>> with 3 ground pins...
>
>> My question is - what if one or more of the ground
>> pins were not connected, would the drive still work
>
> Yes.
>
>> and if so is it dangerous?
>
> Nope.
>
>> i.e. must ALL 7 pins be connected before the drive will work/be seen by XP?
>
> The 4 data lines are crucial, not all the ground lines are.
>
>

http://www.sata-io.org/docs/serialat...technology.pdf

"Serial ATA – 4-wire cable with support for optional shield / drain wires

Serial ATA uses a minimum 4-wire cable that includes differential pairs for
transmitting and receiving data. To minimize impedance and crosstalk, many cables
incorporate additional shielding ground drain lines which function
similarly to the 40 interspersed ground lines in the 80-pin Ultra ATA cable.
The Serial ATA connector supports 3 independent ground return paths. Serial
ATA cables are specified to be at max 1m in length."

If I had to choose a ground pin to break off, I'd want to choose one of the
outside ground pins, and not the one in the center.

Paul

Paul <nospam@needed.com> wrote:
> Rod Speed wrote:
>> gavin@my-deja.com wrote:
>>
>>> Further to the issues I have been having with a broken SATA
>>> data connector (which still works after being wedged on!)
>>> I was wondering about the pin arrangement on the
>>> connector. I note there are 2 transmit and 2 receive pins
>>
>> Each pair is a balanced pair, like with a twisted pair in a cable.
>>
>>> with 3 ground pins...
>>
>>> My question is - what if one or more of the ground
>>> pins were not connected, would the drive still work
>>
>> Yes.
>>
>>> and if so is it dangerous?
>>
>> Nope.
>>
>>> i.e. must ALL 7 pins be connected before the drive will work/be
>>> seen by XP?
>>
>> The 4 data lines are crucial, not all the ground lines are.
>>
>>
>
> http://www.sata-io.org/docs/serialat...technology.pdf
>
> "Serial ATA – 4-wire cable with support for optional shield / drain
> wires
> Serial ATA uses a minimum 4-wire cable that includes differential
> pairs for transmitting and receiving data. To minimize impedance
> and crosstalk, many cables incorporate additional shielding ground
> drain lines which function similarly to the 40 interspersed ground
> lines in the 80-pin Ultra ATA cable. The Serial ATA connector
> supports 3 independent ground return paths. Serial ATA cables are
> specified to be at max 1m in length."

> If I had to choose a ground pin to break off, I'd want to choose one of the outside ground pins,
> and not the one in the center.

I doubt it would make much difference in practice.

And its certainly not dangerous in the sense of killing anything.

Rod Speed wrote:
> Paul <nospam@needed.com> wrote:
> > Rod Speed wrote:
> >> gavin@my-deja.com wrote:
> >>
> >>> Further to the issues I have been having with a broken SATA
> >>> data connector (which still works after being wedged on!)
> >>> I was wondering about the pin arrangement on the
> >>> connector. I note there are 2 transmit and 2 receive pins
> >>
> >> Each pair is a balanced pair, like with a twisted pair in a cable.
> >>
> >>> with 3 ground pins...
> >>
> >>> My question is - what if one or more of the ground
> >>> pins were not connected, would the drive still work
> >>
> >> Yes.
> >>
> >>> and if so is it dangerous?
> >>
> >> Nope.
> >>
> >>> i.e. must ALL 7 pins be connected before the drive will work/be
> >>> seen by XP?
> >>
> >> The 4 data lines are crucial, not all the ground lines are.
> >>
> >>
> >
> > http://www.sata-io.org/docs/serialat...technology.pdf
> >
> > "Serial ATA - 4-wire cable with support for optional shield / drain
> > wires
> > Serial ATA uses a minimum 4-wire cable that includes differential
> > pairs for transmitting and receiving data. To minimize impedance
> > and crosstalk, many cables incorporate additional shielding ground
> > drain lines which function similarly to the 40 interspersed ground
> > lines in the 80-pin Ultra ATA cable. The Serial ATA connector
> > supports 3 independent ground return paths. Serial ATA cables are
> > specified to be at max 1m in length."
>
> > If I had to choose a ground pin to break off, I'd want to choose one of the outside ground pins,
> > and not the one in the center.
>
> I doubt it would make much difference in practice.
>
> And its certainly not dangerous in the sense of killing anything.

Thanks guys, just wanted to check if I was lilely to come home to a
pile of molten plastic if the ground pins were not connecting properly
:-) I know the ground pins are slightly staggered on the drive so that
the connect last hence my concern.....