Order picker does not go through start up. No codes displayed.

Crown Order Picker SP3020-30

Solid amber light on Steer Module.

1) changed steer module - no change
2) changed steer encoder - no change
3) found burnt distribution board. changed distribution board - no change

i'm thinking there is a wiring issue somewhere that caused the distribution board to burn out, but i don't have a wiring schematic that would allow me to trace it.

Does anyone have any ideas or an appropriate wiring schematic that might help?

Thank you in advance.