1394A external device can't be recognized

techo

hi All,
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$ H+ Y& ?! l" i& A, T8 S, T1 q0 Yis there any one had experienced 1394A external device can't be recognized under OS?
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I encounter this kind of issue recently.
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6 J6 |- y- E3 h! }, JOS is Vista & XP.

- y" W1 i5 |, z1 k, E& k- B* K1394A 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.
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2 x* ~, k4 m  S# Iindeed 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?

% t5 ]' l1 i6 W/ L" d8 f& U) }. yis there any spec or document could let me refer to?

Thanks anyway!