Common electrical faulties of VSX-1019

My current VSX-816S which i've brought about 1 1/2 years ago tends to produce abnormal cracking noise problem (LH side front speaker)when the receiver was warm up or operated for about an hour or more. I've tried to swap another pair of book shelf speaker to the front channel & the same phenomenon still occured. Therefore i am sure that this wasn't the speaker's problem. I believe that the root cause might due to the sound IC defect. Does this faulty appeared to happen on the VSX-1019 model? What are other common electrical faulties that would occured to this model? Really appreciate the comments from you guys. Thank you...