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@Kilgore ! You're in a very similar situation to my current VECTOR project, it too was missing the transformer, some of the cable looms and some of the looms supplied were from different games! I bought a transformer from Ebay and a similar era loom from a kind member on here that I've been adapting to purpose. I had a complete VECTOR sitting right next to it to help and it's still a challenge (but fun). My shop log on here will give you a flavour of what you're up against;
http://www.pinballinfo.com/community/threads/viva-lost-vector.29530/
It sounds like you're missing (at least) what Bally calls "A2 Power Transformer Module", which is the mounting plate, transformer and rectifier board. There are several Bally transformers, I'd start hunting one of these down. If that has gone other parts may have been pilfered if this had become a spares machine.
http://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Transformers
I'm not sure what your motivation was for taking on a project, its rewarding bringing machines back from the dead but can be costly in time and £££ vs sensible purchases of complete examples.
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