further to 5xusb- 3x1394 pci card ? :-)

  • Thread starter Thread starter RJK
  • Start date Start date
R

RJK

....pci card installed by XP beautifully in seconds !

NEXT problem:- I think I may have discovered a problem in my 3 1/2" bay
meemory card read, (which has a 1394 plug hole on the front of it, which was
why I wanted a 1394 pin header on a pci card) !

Re: http://pinouts.ru/Slots/ieee1394_pinout.shtml the 1394 plug diagram on
this page.

....while I was trying to work out for myself, (with tester set to
continuity), which internal "fly lead" from the back of the card reader /
went to which pin on the 1394 pin header on this blooming pci card, I
discovered that pins 5 and 6, (TPA+ and -), appear to be connected together,
inside my 3 1/2" bay card reader. i.e. the tail lead connectors TPA+ and -
BOTH read closed circuit on either pin 5 or pin 6 in the 1394 plug hole
....if you see what I mean !

....any ideas, ..e.g. exotic circuitry that means that pins 5 and 6 suddenly
become isolated when the PC is switched on , ...well i can clutch at straws
can't I !!

....any views appreciated.

regards, Richard
 
RJK said:
...pci card installed by XP beautifully in seconds !

NEXT problem:- I think I may have discovered a problem in my 3 1/2" bay
meemory card read, (which has a 1394 plug hole on the front of it, which
was why I wanted a 1394 pin header on a pci card) !

Re: http://pinouts.ru/Slots/ieee1394_pinout.shtml the 1394 plug diagram
on this page.

...while I was trying to work out for myself, (with tester set to
continuity), which internal "fly lead" from the back of the card reader /
went to which pin on the 1394 pin header on this blooming pci card, I
discovered that pins 5 and 6, (TPA+ and -), appear to be connected
together, inside my 3 1/2" bay card reader. i.e. the tail lead connectors
TPA+ and - BOTH read closed circuit on either pin 5 or pin 6 in the 1394
plug hole ...if you see what I mean !

...any ideas, ..e.g. exotic circuitry that means that pins 5 and 6
suddenly become isolated when the PC is switched on , ...well i can clutch
at straws can't I !!

...any views appreciated.

regards, Richard
Click to expand...

There's an old saying that seems to apply to your apparent route. You get
what you pay for.
Dave
 
"There's an old saying that seems to apply to your apparent route. You get
what you pay for."

Very true but, the card reader came from the hardware vendor I've used for
over 20 years and I've never had any problems with it.
It was a new 33in1 or 50in1 card reader with 1xUSB, 1xFirewire, Red/Green
Audio Jacks, and 4x"multi" type memory card slots on it - and it even reads
XD memory cards - which was hard to find at the time !

The tail lead for the single USB socket on it goes to a motherboard USB pin
header - no problem with that.
Have used several types of memory cards - no problems.

As I tried to previously explain, before I found :-
http://pinouts.ru/connector/4_pin,_6_pin_or_9_pin_IEEE1394_FireWire_plug_connector.shtml
....had used my tester to work out which inernal/off the back of the card
reader "fly lead" connector, went to "which" of the 6 contacts inside the
"user firewire socket" (because "they" all seem to use different colours),
at the front of the bay, and along the way, noticed that pins 5 and 6 /
TPA+ and TPA- appear to be connected together !
e.g. if I put one probe on internal "fly lead" TPA+ , and touch the other
probe onto the TPA+ OR TPA- contact in the "bay front" Firewire socket, I
get "closed circuit,"

....which of course makes me very reluctant to connect that port to the pin
header on the pci card I've just installed.
....though, at the end of the day, I suspect that when connected it would be
fine ! i.e. it's probably the nature of the circuitry inside the card
reader, rather than a fault.

regards, Richard
 
RJK said:
...pci card installed by XP beautifully in seconds !

NEXT problem:- I think I may have discovered a problem in my 3 1/2" bay
meemory card read, (which has a 1394 plug hole on the front of it, which was
why I wanted a 1394 pin header on a pci card) !

Re: http://pinouts.ru/Slots/ieee1394_pinout.shtml the 1394 plug diagram on
this page.

...while I was trying to work out for myself, (with tester set to
continuity), which internal "fly lead" from the back of the card reader /
went to which pin on the 1394 pin header on this blooming pci card, I
discovered that pins 5 and 6, (TPA+ and -), appear to be connected together,
inside my 3 1/2" bay card reader. i.e. the tail lead connectors TPA+ and -
BOTH read closed circuit on either pin 5 or pin 6 in the 1394 plug hole
...if you see what I mean !

...any ideas, ..e.g. exotic circuitry that means that pins 5 and 6 suddenly
become isolated when the PC is switched on , ...well i can clutch at straws
can't I !!

...any views appreciated.

regards, Richard
Click to expand...

I applaud your usage of the meter, and the caution you are using.
Firewire devices tend to be expensive, and the last thing you'd
want to do, is damage the interface on your camcorder, due to a
wiring problem.

The connector on the faceplate of the PCI card should be safe and
worry free. If you have doubts, don't take a chance on the
front panel wiring.

In terms of the interconnect, things like TPA+/TPA- are a differential
pair. When properly cabled up and connected to the destination device,
the device at the end of the cable puts something like 110 ohms across
the diff pair, as a transmission line termination to eliminate reflections.
I don't know of a good reason, for a dead short between them.

Section 4.2.2.2 page 18
http://www.1394ta.org/Events/candi_docs/PublicSpecs/2002005.pdf

You might also double check your understanding of the pinout. It
is easy to make mirror image mistakes, especially if the reference
diagram doesn't mention which view of the connector is being shown.
My favorite picture, is PDF page 29 here.

http://developer.apple.com/document...ntosh_CPUs-G4/PowerMacG4Sept02/PowerMacG4.pdf

The power/GND pair (a.k.a VP/VG) on pins 1 and 2, could have a large
bypass capacitor between them. That might read as a short, until the
cap gets charged up.

Paul
 
The two *.pdf URL's you pasted were HUGELY helpful, it looks like I was
EITHER calling pins 1and2, ...pins 5and6 ("mirror image" mistakes that you
mentioned ...that I always spend ages confirming).
OR, I've yet to methodically check everything right through again but, it's
beginning to look like the internal cable from the back of the card reader
bay, terminating in 6 single connectors marked VCC,Gnd,TBA+and-,TPA+and-),
are wrongly "labelled."
i.e. the two marked VCC and Gnd are connected to pins 5 and 6 in the 1394
socket,
....and the two maked TPA+ and TPA- are connected to pins 1 and 2 in the 1394
socket !!

...phew !!

Again MANY thanks.

regards, Richard
 
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