Hi all, new to the forums. I have a question regarding my Denon 2105. I bought this unit as a refurb and it's worked great for about 6 months. Not too long ago I noticed the sound from the center channel started cutting out for no reason. A lot of times when I turned the receiver off then on it fixed the problem temporarily but always came back. Now it seems totally dead. I've connected the center channel to some of the other outputs and it works fine, I've even recut a new wire with no luck. Then I tried plugging the pre-amp for the center channel into a separate amp and wired the speaker to that, still no sound. I'm ready to toss the thing out the window. What am I missing?