JR Continuum 500 Users, question for you..

I have a 12 year old Jeff Rowland C500 integrated amp which in past 5+ years has experienced channel imbalance issues. Recently the left channel Icepower module was replaced w/c fixed problem with distorted left channel output. After the replacement I now hear the right channel as an HF rolled off version of the left channel (softer more polite), creating all sorts of imaging and soundstage problems where instruments gravitate towards the left speaker. This is possibly a problem with the right Icepower module and may need another replacement. This amp has been extremely well cared in a home with no kids, no pets and no smoking, never been driven hard as I live in a busy condo w/ neighbors, and after 12 years still look near mint so I am puzzled on these reliability issues. Maybe a design flaw in the Icepower modules themselves? I am curious if other C500 owners have experienced similar class D module issues.