After looking at the wiring diagram on the TECH SHEET
, I conclude that if there is low voltage to the icemaker, it is coming from the Receiver board as demonstrated in the diagram.
On this board, you can use a paper clip to jumper terminal 3 to terminal #4 (Bk/Wht) to bypass the board and send voltage to the L and N terminals of the icemaker. (door switch closed)
If the icemaker runs (paper clip in T and L) then replace the optics kit.