My 20+ old furnace fan/blower will not work. The furnace starts and heats up just fine but the main fan/blower will not come on. I have trouble shooted the circuit per my manual and have no 110V power coming out of the control board.

Do I need a new control board or is there another switch in the circuit that is keeping the fan from running?

If you have power coming out of the fan terminals on the board, you probably have a bad fan motor. Could be as simple as a bad capacitor.