I have a Glad version of this kind of trash can and your problem sounds exactly like my problem. I took mine apart and determined that all it is is a little spring, probably weighs half an ounce. It basically is strong enough to open the lid with the assistance of the motor, which then closes the lid after 5 seconds by counteracting the spring. It provides enough tension to keep the lid open but not to cause it to open. So I know what to do to fix it, but I don't know where to find the right part. Or how to modify another part to fit the bill.