Quoted from Sonic:
Be sure to check the switches in the 'subway' beneath the playfield - that stages to the refrigerator....as well as the switches for the hole to the doghouse - one of those switches is having an issue...
Like said here, check the optos in the subway at the fridge and make sure the sewer opto in test isn't firing from vibration from the plunge. I would pull those two sets of optos and reflow them also could be a simple cold solder joint. I believe there is only 2 sets of optos in the subway one for the sewer and one for the fridge to stage a ball, if your game is cycling twice its probably is not staging a ball down there. My no fear did that and just would skip it after the second try but it didn't stage the ball.
When I 1st got my JY mine was having issues not awarding the dog shot but once it went in the hole it awarded anything the sewer had lit but my issue was the switch on the playfield at the entrance of the dog house if that switch doesn't register the next thing in line is the sewer opto in the subway then the fridge I believe.