I just got this display for $10 off craigslist. It is plugged in via ADC to my powermac g4 fw800. Video card is an mx4. The USB ports on the back of the display are not working. I have never dealt with ADC displays, so wondering what kind of troubleshooting steps I should take to identify the issue. When a Mouse is plugged in it appears to get power because it lights up, but the pointer does not move. Keyboard does not work either, both ports appear to be affected. Both the keyboard and mouse work when plugged into the USB ports on the back of the g4. I have an ADC to DVI adapter on the way from ebay, so I will try that as well when it arrives. Thanks!