USB Connections to Powered 3rd Party Products

[Guest]

I have two USB apps (an APC UPS & a Jandy digital swim pool controller) that
connect to my Dell 8400 PC. Both products are independently powered 24x7.
When I first connect them, they work. But after I turn off the PC & restart
it, neither works.

They both worked fine under Windows 98SE, and even though I've upgraded both
software pkgs to XP, neither works. I've tried Compatibility Mode too, to no
avail. Other than telling me to upgrade their software to XP, neither 3rd
party hardware firm has been helpful.

It would seem to be the USB driver, but I've also downloaded Microsoft's
latest. What am I missing?

 

[R. McCarty]

Devices will "Vanish" if the total current drawn exceeds the maximum
of 500mA per root hub. What happens if you just connect one at a
time ?

 

[Guest]

No help, Roger. I have puled teh Jandy plug & the APC UPS is still in &
doesn't communicate (when I boot, it reports that this hardware wasn't
found). Of course, it is there, and if I unplug & replug, it will work one
time.