I recently hooked up a Motorola DVR cable box to my Onkyo 702 reciever using optical audio. I worked fine for a while with great dolby digital 5.1 sound on all the HD channels(despite a clicking sound from the reciever when I switched channels while it detected if it was a digital signal or analog). I was trying to adjust some reciever settings and now have no sound at all. lesson...if it aint broke... Any ideas?