B&K Noise

I have noticed that I lost my L channel from my B&K. I have swapped out cables and reverse the polarity of all cables insuring that I have made the proper connection. I also tried the L speaker with the R and it works fine. All I hear is noise distortion even when the amp is powered off.
Has my L channel been blown out? Any help or advise is greatly appreciated. Al
Have you contacted B&K? They are normally very responsive, start with an e-mail and then make a phone call.

Any fuses?

BOL, doesn't sound very good.
Yes I've contacted BK and shipped the receiver back, they were very responsive. I sent this out to avoid shipping item back to BK, but I tried everything. BK has repaired the channel and pending returned item.