I'm sure that schematics reading has been covered in the text of other posts, but a quick search by topic doesn't return anything useful for "Reading Schematics". So, as simple as it sounds, I just want to create a topic on the mattter that is easy to find (and I need advice, too).

When reading a schematic (I'm currently looking at a Gottlieb 1975 Quick Draw schematic), should I "imagine" the current flowing in one direction? It seems obvious at first (follow the line-in / transformer lines), but then some circuits seem to go in a loop of sorts, and I'm not sure if applying directionality is correct in the first place.

Also, since Gottlieb schematics are shown with the machine powered down, but with Player 1 / Ball 1 ready to go, some of the motor / stepper switches are confusing. Am I supposed to read the schematic as "So when you turn the game on, it will be in a ready-to-play state", or "when you turn the game on it will first cycle the score motor and any steppers that need cycled and then you can play that first ball"? It seems to make a difference if I am supposed to know that a switch should be closed while off or that it will be closed if such-and-such happens after powering on.

Obviously, the Hold relay and Tilt Hold relay (and Coin Lockout relay?) will be energized once the machine has power, but do I treat those Hold relay switches as closed / open if the game is on or as they are when the machine is unplugged?

I've already looked over Clay's helpful advice on Gottlieb schematics on Pinrepair, but I just wondered what other words of wisdom the Pinside community has on the matter. Thanks!

Oh wow, I started a thread that didn't die right away. Sorry if it was a duplicate (re: post #6) -- I did search for "Reading schematics" before posting this and I didn't get any hits. Great advice, as usual, Dirt.

@SteveFury: Your diagrams and advice are wonderful. This thread will be my go-to any time I need help reading my schematics. I've also seen some of your animations - thank you so much for all the work you put into helping beginners like me understand what my machine is doing (and not doing!). I immediately scanned my schematics after they arrived (because the ink was cracking off at the folds) - great tip! I've found that drawing on the digital copies is far better than using a pencil on the original paper (then trying unsuccessfully to erase my marks).

@rolf: Thanks for the walkthrough on what questions are helpful to ask oneself when looking at a schematic. I found the conversation you and the others have had on her enlightening.

Thanks for commenting, everyone.

@Rolf - I unmarked as "solved" - I wasn't sure what the protocol / etiquette was for that. Since my issues were solved, I didn't want all the awesome posters on here (yourself included) to think that I didn't eventually get my issues solved by everyone's great advice.

I'm not sure what the functional difference is between "solved" and "unsolved" as far as how the thread displays, ends up in searches, etc., but if it is more helpful to other Pinsiders to leave it unsolved, I'm fine with leaving it that way. I'm amazed by the wealth of knowledge this thread has generated - thanks again!