Some days the left outer surround speaker does not work on my PIONEER VSX-LX70 AMP.and some days it works,On days when not working,I have tried all the usual tricks to rectify it like switch speakers,check the cable/wire connections,re-set the Amp to factory default,etc but still no luck.The offending speaker makes a couple of clicking noises each time I change channels on the Virgin Tivo cable TV box.It will either work on the day or it wont.Any idea what is causing this?