This is what’s known as a Master 4 module in a LHM550 Liebherr harbour crane.
Earlier this week it was hit by lightning causing the module to output a combined 8 volts out on the can line 3 circuit.
The rest of the module works fine, all functions work except anything related to can line 3.
Can line 3 output is the 2nd white plug port on the top left of the photo.
I know it’s probably a long shot but does anyone have any familiarity with these kinds of things?
I have added a couple more photos in the comments.
I couldn’t visually see any sort of obvious fail point.
Do you have a schematic for it? That could help pinpoint where a failure causing those symptoms could be. You may also be able to measure the voltages going back from that plug and see where the issue is occurring. But a schematic would be very helpful there too!
I wish we had a schematic.
Even when I worked for Liebherr once a circuit entered a control module it may as well be a magic box Liebherr are very protective of that information.