Also check if the ball shoots out of the thing solenoid kicker to the plastic subway next to the thing box up the back.  The coil holder was broken on my machine and its been broken in a few pictures I have seen of this machine. Must be a common issue. You could easily check it by manually running quick multiball listen for the thing solenoid and then you should seen the ball pass through the swamp to the lock assembly. You may need to remove the swamp plastic. If the ball makes it to lock assembly but the transfer solenoid does not fire-check the switch edges again by rolling a ball down the swamp to see if the switch triggers. You can also go to single switch test mode and select the switches individually to test the 3 switches by rolling a ball down. I have found some times the switches will trigger manually by pushing it but not when a ball is run over it in normal play.   

Good Advice, mine plays up a bit also, "Thing" solenoid seems to be the main issue