On Wed, 9 Jun 2010 17:49:47 -0400, "JoeSpareBedroom"
wrote:

Single width metal door, ancient Genie opener. Door goes about halfway down,
then up again. Disconnected the door from the chain drive and found that it
was imbalanced - the door barely stays open without something propped under
it. Could this be one reason the opener's having problems? Too much weight?


Yes. Have the springs adjusted for balance.