They probably are, but I thought deoxit was supposed to take care of that. I've owned a few of these units over the years & they've all had the same problem with the speaker switches. All the other push button type switches work fine on the units. It's just the speaker ones.
Relay contacts: "I thought deoxit was supposed to take care of that. "
Sometimes, but it can be difficult to open the relay(s) to get deoxit at their contacts. Has this been done?
I don't know the specifics of this model, hopefully someone has more service experience with these Kenwoods than I.
In many amps,generally,there can be multiple places in the signal path where problems have possibilities to occur. But sometimes a flaky switch is just a flaky switch! Looking at each channel's output with a scope, before it hits any relays or switches (and after), will tell a tech the whole story.