Hey there guys.

Here's one day I didn't enjoy. I have a Bally Evel Knievel that has been sitting around for a few years not working at all. I decided to have a good look at it today. I had a good MPU and a good transformer board so I figured I'd have it working in a few hours... yeah, right.

Long story short, my transformer is defective, it drove me crazy trying to get to the bottom of it. I ended up swapping it with another just to prove that I wasn't going crazy after i CHECKED AND SWAPPED just about everything else in the chain. I've never heard of this before, but could see how it might happen, has this ever happened to anyone before? Please share your stories... I just wasted a perfectly good pinball day...

Dan

P.S. If anyone has a spare working transformer let me know. I'd love to get one locally ( due to the weight issue ).

A good lesson.  Hindsight is 20/20 and this would be no piece of cake, but I'm assunming this is why Clays' guides always start with the power supply board (after fuses)...if you can't go forward, then you gotta go back to square one.  GIGO.

Well, I should have explained further, I was at step one - basically.

I only had J2 connected to the transformer board, all the test points were dead, I had just rebuilt ( and tested ) the transformer board so that was a little misleading. I thought something had gone seriously wrong with it. It did eventually get re-tested in another game. Tested OK, which eventually took me back to the transformer itself. I ended up checking stupid stuff, like the on/off switch, varistor, etc... just a waste in the end.

Dan

Never a waste, just eliminates variables.  But who would suspect a transformer. But you have to look upstream too, because shorts can cause transformer problems.   It's probably worth testing transformer leads first, but you really have to know what you're doing, it's not for the feint at heart (or the grounded at the elbow either).  

Strange...

Is the transformer itself suspect, or is it more likely the rectifier board attached to it ?
Transformers very rarely go bad... Although they might burn if overfused with a short on the load...
Or if a wire is broken leading to it. Or incorrectly set (voltage jumpers).

Usually, a cold solder joint, bad connector or bad bridge rectifier is the problem on the
rectifier board...

Have you checked the voltage adjust jumpers on the transformer ?
(just in case).

Edit: Many consumer-grade devices that have small AC transformers often have a thermal fuse
inside the transformer wrapper itself; I do not think that the beefy transformers used in these
early Bally SS machine had those...

Good luck !
- Sylvain.