I have a DF2603 unit (about 10 years old). Remote control does not turn unit on or off. Changed battery. no luck. Also tried to initialize the remote control. Tid not work. What do I do next? Also, manual says the control panel has power I and Power II on same button. MY unit does not have that. I have two separate power bottons. One on each side-top front of unit. Do theses buttons on the unit have to be in the I or O position?