Home Theater Questions? Ask a Technician for Answers ASAP
Hello, Light coming from the cable does not mean the cable is fine. You'll see light even if the fibre is broken- it has a refractive index which is what focuses the amount of light to be read and decoded. I'm not saying 100% that is the problem, but it is a possibility.
So, have you tried resetting the Onkyo to defaults yet?
Do you have another optical cable you can try?
Please let me know when you're able to see my reply.