Agree with jdsmoothie!. He is an SME in this area. I too had this happen on Thursday, with a receiver that has not moved in a year. I do have a couple of speaker cables without banana pugs, and would you know it, it was one of the four cables. I re-twisted them and tightened the knob, and the red light went away and all is well. I did order a few sets of banana plugs that should be in today.