Help Amp Output 4 Not working

I subscribe to a sat TV that has a music channel in HD and Dolby 5.1. Instead of engineering 5 channels, it sounds to me that they send out the music equally on all 5 channels. Thus, it is pretty easy to tell if one of my rear speakers is not working.
I have a Krell Showcase amp with 5 Channels. I've done every combination like switch speaker connections from the speakers and switch the channel inputs from the Krell Showcase proc. All the cables and speakers and the outputs on the proc work fine. It came down to either the #4 input or output on the amp. I even tried the balanced and the rca inputs on the 4th channel.
unless you smell burnt silicon then it is most likely a mechanical failure, like a loose connection or something like that.

when an amplifier fries a component it will produce quite a strong odor, even if it blew out a month ago, a deep whiff near the vents of the chassis will reveal the pugent smell of fried electrical component. in which case it needs to be sent in for repair.

most likely it is just a loose output connection, you might be able to fix that yourself.
Pop the lid and look for a blown fuse. If you somehow touched the cable ends together you can blow a rail fuse, the little glass ones that look like tubes with metal caps. Then you can go to Radio Shack and pick up some new ones and be back in business...Jim