How do I reset my digital bathroom scale after changing the battery?

My digital bathroom scale started displaying "Lo" so I changed the 3V battery. Now it flips between a bunch of weights, goes blank, displays "Err" and ends on a totally random weight. There is a switch on the bottom that has 3 positions: Kg, ST, and Lb. There were no other switches that I could find. How can I reset the scale or am I going to be scale shopping for a new one?