1394A external device can't be recognized

techo

hi All,
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is there any one had experienced 1394A external device can't be recognized under OS?

I encounter this kind of issue recently.
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OS is Vista & XP.

9 U& @  f# m$ R4 }1394A controller is Ricoh.
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the situation is I could see the removable icon shown on the system tray but there is no device in OS device manager.

indeed there are some differents but I don't know why.
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I wonder it's caused by BIOS but how to prove it?
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& p1 b; V' O- O" pis there any spec or document could let me refer to?
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$ p" k3 s8 z3 n) H" P% o. QThanks anyway!