9 pins are used for two USB connections. I do not know if
your card reader needs two. Does it have a USB socket in it
as well as card reader slots? If not, I would suspect it
only needs one connector which is 4 pins in a row out of 5
(Or 4 plus the empty pin position), that they only made it a
9 pin so that people wouldn't accidentally plug it in
backwards... but I could be wrong.
If the 5V, ground, data +, and data - pins are not in the
right positions to correspond to the pinout on your
motherboard, you can take a small thin tool like a knife
blade or a needle and gently flex up small plastic tabs on
the connector body to allow pulling out the wires and
switching their positions. In the following picture the
arrow points to where the small tool would be inserted to
flex the locking tabs.
http://69.36.166.207/usr_1034/pins.gif
As I wrote above, I would assume it only needs 4 or 5 pins
and try it, but you need to be sure the pins have the same
logical arrangement, the positions of 5V, data +, data -,
and ground.
I don't know. I would use a multimeter to determine which
pins on the card are 5V and ground, and compare that to
which pins need to be 5V and ground on the card reader. An
examination of it's PCB might tell you, or if the cable has
colored wires then 5V is usually red, ground is usually
black, data + is usually green and data - is usually white.
It isn't very complicated if you can figure out which pins
have which functions. There is another alternative, to just
buy a different card reader since they only cost about $10.