Audio Systems: Denon AVR4802, stereo cables, demux

Question
This receiver has 3 digital audio coaxial inputs. all 3 have quit working 1 by 1 while having my cable box in that slot. they did not blow when my dvd was in those spots. now I have settled for TV R/L stereo cables.  Why is my cable box output causing this and what parts do I need to repair those input jacks??
Thank You in advance for your help!!!

Answer
The demux has input limitations. Probably the cable input level is too high and overloads the inputs of the digital inputs.

You must contact with Denon service to get it repaired. I would not trust a local service agency.  Make sure it is an authorized Denon factory service center. They have quite a few of them around the country.

There may be attenuators the cable company or Denon can supply you with to keep the levels in check.

Hope this helps.
C