CS-ELE09100205 CIRCUIT BOARD C2100R1C To determine what board you have look at the lower left corner and on the black computer chip. --------------------------------------------------------------------------------------------------------------->>>>>>>> VERY INPORTANT: IF YOU BOARD NUMBER ENDS WITH A LETTER THE REPLACEMENT MUST BE EQUAL OR GREATER TO REPLACE THAT BOARD. EXAMPLE: C2100R1C --- THIS CAN BE REPLACED WITH A C2100R1C - R1D - R1E - R1F ETC -BUT NOT A R1B OR A R1A BOARD.