Problems with USB on ADS Dual Link 2.5" enclosure

[Markeau]

I have 2 ADS Dual Link 2.5" drive enclosures that were bought 1yr
apart. Both work fine with their 1394 ports with multiple drives on
multiple XPpro SP2 systems. But these 2 units do not work via USB
with the same drives and systems.

Via USB the drives do not spin up at all after connecting them, but
again if I try 1394 the drives spin up, mount and are readily
accessible. I have tried different USB cables, all of which work fine
with my other ADS Dual Link 3.5" enclosures.

It seems like the drives are not getting power, but the installation
instructions say that only the single USB cable is necessary - and so
the drive will get power from it.

I am connecting to the USB ports directly on the mobo's, not going
thru a hub. Device Manager shows "there is a problem with the
device", but nothing else. And there is no driver install dialog
displayed when the drive is connected. All other Dual Link 3.5" drive
enclosures work fine on these systems.

Has anyone else experienced this?

 

[gypsyman]

Answer:
While the supplied documentation does not mention it, TWO USB cables
must be used with this unit - one has a round power connector that
plugs into the enclosure.

Now that I've looked around, so far all other 2.5" USB enclosures are
advertised as "bus powered" and the pics seem to indeed only show one
connector. So, is ADS the only one with the "dual USB cable" design?
Seems absurd.