5.1 Reciever Upconverting How To Check To See If Any Channels On My 5.1 Home Theater Reciever Is Blown?

How to check to see if any channels on my 5.1 home theater reciever is blown? - 5.1 reciever upconverting

Is it possible that you or I could be doing something to check to see if I have an idea, maybe, I mean that I have a piece of a very nice Sony receiver later than my brother the exact same model and There is no problem only that its very quiet at times and others may be strongly idk, but it's a way to check to determine whether a channel is blown?