Problems with my Tri-Vista 300--Need some help


My new Tri-Vista integrated has worked beautifully for a month, but yesterday, for the first time, I discovered that no sound is coming through the right terminals into the speaker. I tried shifting speakers and cables around and found that it has to originate with the amp. The amp has two sets of binding posts, but in changing the speaker cables to either of them, I've still gotten no sound out of the right side. Could this be a problem with an internal fuse, and if so, and since I have no MF dealers here in Korea (I bought off the net), what might be my options in terms of getting the amp repaired? Any suggestions?
washline
check that. Inexplicably, the source selector has started to work properly again. Don't know why. Who can figure out the idiosyncrasies of circuits and electricity. I'll keep my fingers crossed in hopes that the selector continues to work properly. In any case, what a gorgeous sounding amp.
Timf, I thank you very much for your post. It seems as though our problems are very comparable both in development and solution. Like I said, who can truly grasp the strangeness of circuits and electricity. Even the best equipment can develop such strange, seemingly uncaused problems.