i have the same receiver (ht-r410) had the same problem like a week after a bought the system, i try the fan thing but no result promblem was still there i brought it back to the store were i got it and many tests were done on the receiver until they gave up and gave me a new one seems to be a very common problem with this receiver i recomend if you still under guaranty try to get a new one problem will stay there and will only get worse with time.
Carlos M.
November 2005