I can't answer you question directly, but thought this information might help. If you already are aware of this information, please excuse me cluttering up your thread.

Pinwiki is a great source for infromation for general pin information and repairs. Information for Williams System 11 games can be found here http://pinwiki.com/wiki/index.php?title=Williams_System_9_-_11#Power_Supply.

If you are going to working on the game your self, I suggest getting the manual/schematics from Steve Young at The Pinball Resource http://www.pbresource.com/mansch.html#manaval. You cannot order online as his ordering is limited to phone or request by email. However, they are helpful and ship quick.

Hope this helps.

Thanks for the reminder RCA1, I been working on a Gottlieb pin for awhile and forgot that some other manufactures manuals can be found on IPDB.