Help with Cambridge Audio

I have a Cambridge Audio 640R Receiver, and two of the Optical link ports are bad, Of course the two we use the most, the DVD and TV. I took it to a local repair shop, and he is saying he cant find replacements for these. Can anyone help me locate them?
As a last resort, monoprice has converters for optical to RCA if your unit has that. They also have switch selector devices so you can choose between sources if you only have one digital in. $18 for both.
CA seems to save all its QC for CD players.