A gorgeous day here in South Jersey, swimming & B-B-Q under way, then I went to put my Sonos system on to the outside deck & low & behold only one of the Polk Atrium 45 speakers are working. I started the usual "What the F%$#*) & started delving into what might be the problem. Then I spotted the banana jacks on the speaker...just as green as Patty's pig!! Down to the work shop for some fine grit sandpaper & rubbing alcohol. Cleaned them up lickity split & did the other speakers banana's as well. Fired the system back up & good as gold. Then I started to think that the speakers have been up for over 4yrs & I never checked them before. Now it will be a new spring time project to clean them.