Thanks for the response and background info. When it didn't work just looking at the wiring it would've been my next guess. Wish I knew it was the more common problem for this model before i dropped the 200+ on the interface board. 50/50 chance i guess, between appliance doc's response(on different model) and repair clinics description of part as "If the washer won't start the main control board might be defective. This is not common. Check other parts and causes first." I went with the interface board.
What point should i check for power at the main board? I didn't go further than the plug b/c my fluke leads were too big to reach the contacts inside connector. Or do i have no reason to believe that this part wont be the fix(can't imagine too many other problems for my given symptom)?
Semi-related; got any suggestions on a good place to post/sell a once plugged in, never actually seen voltage , interface board? Since i cant return it anymore