"John said:
My A7N8X comes with 2 firewire ports and the expansion
bracket that connects to the motherboard. However on the
motherboard is a place to take 2x5 pin connector that is
labeled "IEEE1394 3". I only just noticed it because my
new case has a front firewire port and the cable doesn't
fit the existing connectors, but it would fit the missing
connector if I soldered in some pins.
Has anyone tried this?
P.S. My case is an Antec Sonata. All the front connectors
fit the MB except for the firewire.
According to this, the Nforce2 Southbridge has three firewire ports.
But these are the MAC layer only. The PHY that drives the cables
comes from a separate chip.
http://www.nvidia.com/object/IO_20020715_4484.html
This is the chip Asus is using for the PHY. It is _2_ ports.
http://www.realtek.com.tw/search/search.aspx?search=8801b
If you look at a picture of the motherboard, in the downloadable
PDF version of the manual, the wiring almost looks like the 1394_2
header and the 1394_3 header are wired in parallel. That means
you can only use one of the two headers at a time. If nothing
is connected to _2, and you install pins in _3, connect to the
Sonata cable, it just might work. (Now, if this is true, and you
can verify this visually yourself, it also means Asus has put a
copper stub off a 400Mb/s signal - not a good practice!)
Based on my experience with Antec cases, do not trust them to
wire the connectors properly. Always verify with an ohmmeter, that
a particular wire on the 2x5 end, goes to the correct pin on the
Firewire connector. You can get pictures of Firewire pinout from
the net, and then you can check what Antec has done.
http://developer.apple.com/document...ntosh_CPUs-G4/PowerMacG4Sept02/PowerMacG4.pdf
Using the picture on page 37 of that document, this is what you
see when looking into the connector on the front of your
computer case.
1 3 5
______________
/ 12V B- A- |
| |
\ GND B+ A+ |
--------------
2 4 6
1 Power (12V on a PC)
2 Ground (power return is same potential as shield on a PC)
3 TPB Twisted-pair B Minus
4 TPB+ Twisted-pair B Plus
5 TPA Twisted-pair A Minus
6 TPA+ Twisted-pair A Plus
Shell ‹ Outer cable shield
Rather than solder pins to the motherboard, an easier solution
is to find a plastic connector body (shroud), then pull the pins
out of the Sonata 2x5 and insert them into the new 1x8 body.
The pins can be removed by depressing the metal tab on each pin
and pulling the wire and pin out of the 2x5. The pin can then
be snapped into its new housing.
The Sonata has 7 wires: +12, two GND, TPA-, TPA_, TPB-, TPB+
The motherboard has three grounds, so one ground pin will be
unused. You could shop for a 1x8 pin connector body here:
http://frontx.com/order_c.html
http://frontx.com/cpx075_7.html (a 1x8 connector body)
Many electronics stores should have stuff like this as
well. Take the frontx URL with you when you go shopping.
HTH,
Paul
