[brassicGamer]

Thanks for your time on this, I really appreciate it. I thought I would list the component labels identified in case it further helps others dealing with a similar issue. I found only found two failed components.

Optocouplers (as arranged: left to right, top to bottom):
IC402, IC481, IC401, IC501, IC552, IC553, IC441, IC442

Resistors (27 Ohm):
R420, R417, R485, R482, R413, R415, R416, R414, R449, R448, R453, R452.

Resistors (15 Ohm):
R490, R489, R572.

Resistors (330 Ohm):
R576.

Resistors (2.2k):
R577.

Resistors (39k):
R571.

IC501 is closed, but all the resistors are reading their expected values except for one of the 2.2Ohm through-hole ones (R283). Time to salvage replacements!