Success!!!!  (kind of....).

Just got home and decided to bend the loose wire on the leg of the switch as tight as I could (until I soldered it properly). Turned the machine on and pressed start. The score motor spun continuously and the Coin Unit stepper continuously clicked and wouldn't stop. I turned the machine off, flicked the Game Over relay latch manually and wound up a heap of credits on the credit wheel in the head. I also moved the Coin Unit by hand off zero and then put the playfield down and the ball back in the trough.

I turned the machine on again and noticed Game Over on the backglass was lit. I pressed start, the machine did its startup/reset sequence and this time the ball flung into the shooter lane and my jaw dropped. This is the type of thing that keeps me going. I had a game and the ball drained. It didn't kick out again. I kept pressing the start button and the ball would randomly kick out every 5th time or so. I decided to turn the machine off and call it a night.

We're getting somewhere! Time for that systematic approach.

Cheers!
Adam.