While agreeing about the dubious quality of Xantrex, from a technical point of view, that board doesn't look physically too bad.
If you removed a couple of parts
, cleaned out the salt
and replaced them, you might get it going again.
The rusty transformer would be my first remove, clean replace project
As long as it's toast, don't laugh, but you can always put it in a dishwasher, run it on the hot water
cycle, let it dry in the sun and breeze or a really warm spot for a couple of days and it might work.
I used to do that when I repaired VCR's for a living.
People would spill all manner of liquids in them, so I'd remove the affected boards, wash and dry them and replace after fixing any corroded stuff.
It was S.O. P. for about 2-3% of the jobs.