My model 139.53985D garage door opener is 3 years old and out of warranty. For more than a year the room light on the swicth has has worked intermittently, burned through many light bulbs and now doesn't cvome on at all. It was OK as the other light was suffcient. Now the other light comes on intermittently so we find ourselves stumbling in the dark. Any idea what the problem is and whether a weekend warrior like myself can repair it? If I have to have a Sears repairman out, it will cost as much as the original unit for parts and labor.