Acoustimass 6 - Indiscriminate "popping" noise

[larryntripp]

I have an Acoustimass 6 series III system that has been working perfectly for many years, but recently my system has begun to "pop".  The "pop" occurs indiscriminately and there seems to be no pattern to it.  Sometimes it will go for hours without popping, other times several pops occur in a short period.  It happens on both live and recorded programs.  

I have not isolated this problem specifically to the Bose, it is possible it is originating upstream from the speaker system in one of the other home theater components, but wanted to see if this is a problem likely to exist with the Bose Acoustimass and if so, how to diagnose and fix it. 

Thanks in advance for any input.