About a year ago I pre-ordered a Lionel U30C - a much later loco than my early-50's layout's theme, but any locomotive called a "U-Boat" . . .
It ran well but had occasional stick-in-neutral anomalies. Jon Z at Lionel offered to look at it. In what was one of the most embarrassing things I've ever done, I shipped him my trusty older SD70 instead (Hey, they are kept one above the other on the shelf and they look a lot alike, particularly with both are in UP livery).
Anyway, he returned the SD70 along with the new replacement board for my U-boat, and when I went to install it - well, I cracked the shell putting it back on. Badly. Two pieces . . .
So I ordered a second one, and when it arrived, it would not get out of neutral, period. Not on a Z4000. Not on a CW80. Nothing i could do -- neutral, with those great U-boat idle sounds tantalizing me . . . but no movement. I was too embarrassed to send it back to Lionel, and not about to take it apart. So I concluded I was jinxed as to U30Cs and put it up on the shelf.
This morning I was up in the train room waiting for my 24 test to complete, and on a whim I took it down and put it on my #3 loop, and . . . it ran perfectly. O joy! What a great locomotive! It has just fantastic diesel sounds. I swear I can hear the valves (or tappets) at idle.
My luck has changed, I think. Maybe it was the 24 hour test, or maybe that little Y6B I ran for a day had some magic in it. 
