The only class that will really help with pinball machines would be a class that does a lot of circuit board building and repair. Most electronics or engineering classes are going to spend more time on circuit theory.
I spent 4 years getting a electrical engineering degree at a major university and I never learned anything from them about soldering. What I know about soldering I have learned on my own (which is not much). Most electrical engineers that have 4-year degrees are paper pushers rather than circuit builders.

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I would think that you only need 3 of those DVD sets for Pinball repair:
1. All You Need beginning electronics...
2. Diodes, Transistors, other semiconductor..
3. Easy pinball PC Board repair

Which is about $130 total.

Has anybody tried these DVD's? Are they good?

Or you could get a 9 volt battery, some wire, and appropriate sized capacitor. If you assemble them in a particular way and put the vinegar into your skin just right, it could be fatal.
When I was in engineering school our professor told us how an MIT student died this way after eating a sandwich that had vinegar in it which he managed to get on his skin. DC current is hazardous to your health

Of course, the good thing about the paper pushing from my experience as an EE is that it usually pays more than hands-on work.