Xenon owners please confirm switch 28 is open or closed, with balls out. In switch test. I think the gap or switch is stuck on .
Wait for a response from a xenon owner.

 Then Do the switch test again and test with and with out balls. And double check with other owners .
Also adam ,how many balls in xenon 2?

I hope i am not leading you astray.

I think, this is the extent of my trouble shooting skills. Got me stumped. Next i would swap board to see if its board related.? Not sure??
 I will leave the rest of the comments to the more experienced.

$500 offer is now looking better. Or some under water pinball could be fun.