Thanks for the tea and sympathy l feel a bit better now....
Eric, I took the side panel and back off the 20D last night but there is too much packed/glued in place etc for me to feel comfortable poking around, so I put it back together. The camera works fine and even the usb connection works - albeit only if the cable is plugged in "just so".
Based on Terry's experiance I am off to :
http://www.cameraservicecentre.power...au/default.htm
Tomorrow...~ $100 I can live with....