I have a T6534 eMachine with a K8NGM2 H motherboard. All 5 USB Ports have perferral power but no signal and therefore the USB hardware (like a keyboard, camcorder, ipod, etc) when plugged-in is not recognized. The Windows xp Device Manager indicates all systems are working properly. Uninstalling the USB controllers and Hubs and then letting Windows find them on boot up doesn't help. Disabling all USB from the AMI BIOS settings, rebooting, then Enabling and booting doesn't help.
A possible "work around" would be to purchase an expansion board with USB ports. Before doing that, I wonder if there is anything else I can do to re-establish the on board USB that had always worked before.