Don said some very good things, but I have one to add. When the battery is so dead that it won't even function when you have it plugged in, sometimes the optacon will just plain quit. It won't fire a pin. The first time I had that happen I thought my optacon had permanently died but I sent it to Richard Oehm because he said sometimes that could happen when the battery was really dead and that's all it was. So getting just part of a letter sometimes could just be the battery or maybe it needs cleaning and adjustment. No big deal if you send it to either person recommended here. Gail