One of the clients I service in at my job is a CNC shop.
I was sent to fix one of their CNC routers one day and saw they had 2 pinball machines in the back of the shop. Both were semi functional. The owners of the shop were amazed that I knew anything about them, let alone how to repair them (little did they know). Over the years we struck up a deal of sorts; I'd maintain their machines (CNC & Pinball) and they would give me a corner of the shop to restore Pinballs and let me use their pro downdraft spray booth for clear coating.
This of course has led them to buy a dozen or so pins.
They called to tell me that they bought a mint Williams Time Warp, that had been in a guy's house for 20 years. Time Warp is a really great game and it was one of only 2 Williams games with curved flippers, thus it is rather collectable.
Everything worked on it!
That is, until they got it to the shop. Now every coil locked on upon power up!
The following is a step by step guide to the repair; and required bulletproofing that applies to all Sys6 (and much of Sys3-7).
Deeper into the guide: