I need a diagram for a Rheem criterion 2 gas furnace (RGPH) circuit board
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There should be a diagram on the back side of the blower motor door. This diagram will show where and how the wires are placed on the circuit board. The actual etching of the board or component placement and usege is propritary information and usually not posted by the manufacturer. They want you to buy a new board if the old one is bad and they do not want you to try and repair it since by repairing the board it is possible to put your life at risk from a defective repair.