[SuperBK]

Is your digital IO board in slot 4?

You could try another sidecar, another IO board, or another cable. Check for bent or missing pins on the cable?

By "not talking", what does it not do? control outputs or read inputs?.You could try relay outputs, theres lights for those.

Does it have a power lights? If not, could there be anything connected to it thats shorting it out?

Brian