Welcome to the forum, Michael!
I'm guessing that you are using the same source selection (e.g. "DVD") for your new blu-ray player that you had been using with the old DVD player. If so, I bet that you just need to assign the optical digital input to that source.
That will be explained in your owner's manual, but if you have any questions about how to do that, just let us know.
EDIT: It's on page 18 of your owner's manual (you can download a PDF from Onkyo at the link
here if you don't have the manual handy).