Need a service manual

Bought a gently used LG WT7400cv.ASSEUUS washing machine... Supposedly worked fine.

It does not.

I would like to troubleshoot it, but I will likely need a service manual (not an owners manual)

Any one know where I can find one?

When set to run in any mode, the 'sensing' light flashes, and it never moves on to fill or wash or anything. It just sits there sensing.

I set it on 'tub clean', thinking it would not need to sense for that - it filled the tub, and sat there doing nothing. The timer did not advance.

Any ideas?