Sound Hack for USB HK Soundsticks

Recently came into the posession of a Harmon Kardon Soundstick system, it's got the woofer, power supply and the two tall sticks.. The sub inputs via USB and therein is the issue. The Console in the living room Frankenbox, in my G4 MDD, the MacPro and the MacBook Pro all report:

4/16/14 11:50:05 AM USBF: 64063. 99 [0xe729700] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 1 of Hub at 0x1d000000) kernel

4/16/14 11:50:09 AM USBF: 64066.227 [0xe729700] The IOUSBFamily was not able to enumerate a device. kernel

SO, obviously some part of the USB audio has gone up the spout, and at this point, I'd be satisfied to bypass the digital audio, work a standard line-in onto the circuit board and haul the USB connector right out and hook straight into the built-in amplifier that DOES work - I had this running fine on the MDD G4 a few weeks ago - that's a dual-boot with OS 9.2.2 and Tiger - it worked fine under both OSes - and it stopped working two days ago.

Here's the board pulled out of the case, as you can see it appears perfect, so what the issue is may be down to a bad chip.. Any ideas on where to go (other then the dump!) with this?

http://home.comcast.net/~foodandart/DSC00745.JPG

Thanks,

Deb.