sara, if you are still there, i just had the same problem on my marantz 1030 fixed by having the switch replaced. no other way that i know of. switches can be found sometimes on ebay, sometimes with vintage audio collectors, or perhaps at a place called audio classics in vestal, n.y. (www.audioclassics.com). craigslist is another possibility--i chanced upon an ad for vintage stereo equipment repair and got my amp fixed for $65. hope this helps.
victor
February 2008