If no devices work when you plug the devices into the root hub, verify that the
power requirements of the bus are not being exceeded. USB devices can draw a
maximum of 500 milliamps for each connection. If a device attempts to draw more
power than this, the specification recommends that the computer should be able
to disable that specific port until the computer power is cycled (this is called
"suspending" the port). In addition, if the device draws less than 50 milliamps,
the port never becomes active.
Check the Power tab in USB Root Hub properties to check the power usage of the
USB bus.
*****************************************************************************
......So what about externally powered USB enclosures/USB Hubs that don't draw
any power from the USB 2.0 port? They just don't work?
I had a USB 2.0 enclosed internal drive working in early December, now it
doesn't work on the Win XP machine without an overrun of Event 51 errors and
crashes (copying 1.99/2.00 GB image files to the USB drive). The drive DOES work
just perfectly on my Win 98SE machine now though (copying 700 MB image files to
the USB drive). I think the Win XP machine is too crippled by something to deal
with the USB drive properly anymore (probably by the two Windows Critical
Updates in mid-December, 2005). I'm lucky I was even able to reformat the drive
after Win XP messed it up (used Win XP Quick Format instead). Later on, I tried
the Western Digital Data LifeGuard Tools and it said IT reformatted and
partitioned the drive successfully, when it fact, it hadn't done a darn thing to
the drive and after reboot, the drive looked the same as it did before I tried
to use the Data LifeGuard Tools on it except the locked drive letter assignments
(that Win XP Partitioning had put on) were gone (the Drive Volume Names were the
same as when I partitioned with WinXP Home).
I/O Paging memory errors, something in the registry may be blocking the machine
from working? My two internal hard drives are on a Promise ATA 100 Controller
Card, with a DVD burner and a ZIP Drive are on IDE 1 (good for booting CD/DVD
disks with if the hard drive is turned off in the BIOS first during/for the boot
sequence), and an old DVD-ROM drive on IDE 2 alone (won't work as a boot drive
on IDE 2).
Dell Dimension 4300, 1.6 Ghz, 512 MB RAM
