if you realize these cables are thick, they must be controlled by the relays below, take off each cable and with an ohmmeter you measure continuity with the equipment without unplugged voltage you measure if these contacts are short-circuited or open, run through each power plug, and you are testing connecting the device and measuring what signal is output on each connector, you have to dedicate time, that if very carefully remember that you work with high voltage, a question that rare that those connectors fit in any, usually make them that one does not serve None of the others, I usually take photos and see them before disarming so as not to have this kind of problems and if I have them, I start studying the cto to make the block diagram, it is not difficult, it is laborious, taste in attend you