# Episode 18 - Using Schematics for Troubleshooting **Source:** For Amusement Only EM and Bingo Pinball Podcast **Type:** podcast_episode **Published:** 2015-03-29 **Duration:** 12m 55s **Beat:** Pinball **URL:** https://foramusementonly.libsyn.com/episode-18-using-schematics-for-troubleshooting --- ## Analysis Nick Baldridge provides a detailed technical guide on using schematics to troubleshoot electromechanical (EM) pinball machines, focusing on lamp and scoring circuits. Using Pop-It Card (1971 Adaball) as an example, he demonstrates systematic troubleshooting methodology and explains how to interpret schematic symbols, relay abbreviations, wire color codes, and manufacturer-specific notation conventions across Gottlieb and Bally machines. ### Key Claims - [HIGH] Pop-It Card is a 1971 Adaball EM pinball machine — _Nick Baldridge stating factual product information about the example machine used in the episode_ - [HIGH] Most EM pinball schematics show the machine in a startup state with the first ball unplayed in the shooter lane — _Nick Baldridge describing standard schematic representation conventions across manufacturers_ - [HIGH] Gottlieb used single and sometimes double letter abbreviations for relay units, while most other manufacturers named units more explicitly — _Nick Baldridge comparing Gottlieb notation to industry standard practices_ - [HIGH] Gottlieb's relay naming system (K for 10,000 increment, Q for game over, T for tilt) was repeated consistently through their EM era and into System 1, System 80, and System 3 — _Nick Baldridge discussing design patterns in Gottlieb machine logic and relay function consistency_ - [HIGH] The basic troubleshooting sequence for non-functioning switches is: check adjustment, check for cleanliness, verify switch tab integrity and solder connections, then trace the schematic — _Nick Baldridge outlining diagnostic methodology for switch problems_ - [HIGH] Gottlieb represented steppers as dashed rectangles with multiple contact points, while Bally used rectangular boxes with diagonal lines — _Nick Baldridge comparing visual representation conventions between manufacturers_ - [HIGH] Wire color coding variations: 'yellow plus BL' means alternating yellow and blue colors, while 'yellow minus BL' indicates yellow wire with blue tracer stripe — _Nick Baldridge explaining Gottlieb wire color notation system_ ### Notable Quotes > "the way that I troubleshoot any scoring problem is to work backwards from the coil" > — **Nick Baldridge**, early in episode > _Core troubleshooting methodology for EM machines_ > "if you have a switch that's not working properly, the very first thing you do is check to make sure it's properly adjusted... The second thing you do is make sure that it's clean. And the third thing you do is make sure that the tabs of the switch are still intact and soldered appropriately to the wires." > — **Nick Baldridge**, mid-episode > _Systematic diagnostic approach for switch failures_ > "most schematics show the machine on and the game started but the first ball unplayed. So the ball in the shooter lane and the state of all the switches at that point in time" > — **Nick Baldridge**, mid-episode > _Understanding schematic baseline state for troubleshooting_ > "armed with this knowledge you can troubleshoot practically any problem on an EM" > — **Nick Baldridge**, late episode > _Summary of schematic mastery benefits_ ### Entities | Name | Type | Context | |------|------|---------| | Nick Baldridge | person | Host of For Amusement Only EM and Bingo Pinball Podcast, EM pinball technical expert providing schematic troubleshooting instruction | | Pop-It Card | game | 1971 Adaball EM pinball machine used as primary example for schematic troubleshooting demonstration | | Adaball | company | Manufacturer of Pop-It Card (1971) | | Gottlieb | company | EM pinball manufacturer known for single/double letter relay abbreviations and specific schematic notation conventions | | Bally | company | EM pinball manufacturer with different schematic notation conventions than Gottlieb, particularly for steppers and switches | | For Amusement Only | organization | EM and Bingo Pinball Podcast series hosted by Nick Baldridge | ### Topics - **Primary:** EM pinball schematic interpretation, Troubleshooting methodology for scoring and lamp circuits, Manufacturer-specific schematic notation conventions, Relay logic and naming systems in Gottlieb machines - **Secondary:** Switch diagnostics and maintenance, Wire color coding standards, EM pinball design evolution across manufacturers - **Mentioned:** Pop-It Card (1971) game mechanics and circuits ### Sentiment **Neutral** (0) — Technical educational content delivered in neutral, instructional tone. No evaluative or emotional language; focus is purely on accurate explanation of schematic troubleshooting methodology. ### Signals - **[restoration_signal]** Nick Baldridge providing systematic instruction on reading and interpreting EM pinball schematics for troubleshooting and repair (confidence: high) — Entire episode structure organized around schematic symbol interpretation, relay function identification, and circuit tracing methodology - **[historical_signal]** Comparison of schematic notation conventions between Gottlieb, Bally, and Adaball spanning their EM product lines and into early solid-state systems (confidence: high) — Discussion of Gottlieb relay naming logic persistence through System 1, System 80, System 3; comparison of stepper and switch symbol representations across manufacturers - **[content_signal]** For Amusement Only podcast continuing methodical educational series on EM pinball technical knowledge, building on prior episodes covering schematic symbols (confidence: high) — Episode framing references 'last episode' covering symbols, episode structure builds systematically on prior knowledge, host indicates future episodes will cover score motors - **[design_philosophy]** Gottlieb's systematic relay naming conventions (K=10K increment, Q=game over, T=tilt) revealing intentional design language consistency across product line (confidence: high) — Nick Baldridge noting Gottlieb repeated this logic all the way through their EMs and into System 1, System 80, System 3 - **[restoration_signal]** Structured troubleshooting methodology emphasizing physical inspection before electrical circuit tracing for switch problems (confidence: high) — Three-step pre-schematic diagnostics: adjustment verification, cleanliness check, tab integrity and solder inspection before circuit tracing --- ## Transcript What's that sound? It's For Amusement Only, the EM and Bingo Pinball Podcast. Welcome back to For Amusement Only, this is Nick Baldrige. So, last episode, we left off with learning about the symbols that make up a schematic. Specifically, the symbols that you'll typically find on an EM pinball machine. So today we're going to look for problems in lamp circuits and in scoring circuits. And as an example, I'm going to use the schematic for Pop-It Card. Pop-It Card was a 1971 Adaball EM pinball machine. and the way that I troubleshoot any scoring problem is to work backwards from the coil. As an example, let's look at the right stand-up target. Pop-it card has two stand-up targets and 13 drop targets. the right stand-up target, I thwag it with the ball and it does not score. In fact, it does nothing. So looking at the schematic, I see that the scoring is controlled by the F relay. And working backwards in the circuit, I can see that the right stand-up target is tied to the C relay. If I'm not able to get any action from the right stand-up target, then the first thing I need to do is check out the green wire that comes off of the F coil and trace that back through the C relay, which has a yellow and blue wire leading back to the right target switch. Oh, one thing I didn't mention, if you have a switch that's not working properly, the very first thing you do is check to make sure it's properly adjusted. So if the ball hits it, it actually pushes the switch blades together. The second thing you do is make sure that it's clean. And the third thing you do is make sure that the tabs of the switch are still intact and soldered appropriately to the wires. Then you start tracing your schematic and see what's going on. So this is after I've exhausted the basic possibilities. Now the F actuates a relay and on PapaCard depending on how many targets you have down it will either score points or it will add an extra ball and set off the knocker So if I only have a problem with getting an extra ball, I need to check two different things. Well, three different things. The first would be the knocker itself. the second would be the add ball count unit and the third would be the F relay now there are other things I can check as well assuming that those all check out each manufacturer made their schematics slightly differently so looking at this Gottlieb schematic and noting the differences between it and the ballet schematic I was looking at last night I can see that their steppers are laid out differently. So on Bally, the steppers are in a rectangular box with diagonal lines through it. On this Godlieb schematic, the stepper is in a dashed rectangle with multiple individual points, as in junctions or points of contact, similar to parts of the symbols for switches. This Gottlieb schematic also represents each switch as a momentary push switch, which is different than the Bally schematic I was looking at last night. So each switch, each playfield switch, each pop bumper switch, every switch in the game, in every relay, is represented as a momentary switch. Which really, most of them are. I can't think of any off the top of my head that are always actuated, except for stepper contacts and the lock relay. That would always be, yeah. So, the way that you represent normally open and normally closed, as I mentioned last night, is going to change with the manufacturer and also with the way that the schematic is written by those different manufacturers. So, looking at this normally open shows as two vertical lines which are laid out parallel to each other with a space in between. A normally closed switch will be two parallel lines with a diagonal line connecting them. It's almost like you're marking out the symbol for the switch. It's also important to note what state the machine is in as represented by the schematic. most schematics show the machine on and the game started but the first ball unplayed So the ball in the shooter lane and the state of all the switches at that point in time So knowing that, you can kind of work your way through some problems if you have a startup sequence issue. That's not always the case. it's going to vary from game to game, manufacturer to manufacturer, and year to year. So take a look at certain switches, and that'll give you a clue, like the shooter lane switch, if your game has one, or the ball count unit, which contacts does it say are normally connected. If it says ball one, then that'll tell you that the machine's on and has started its first game. So, moving on to a lamp problem. So, again, we've troubleshot all the very simple things. Dirty sockets, broken switch tabs, bad bulbs, all the simple stuff. And now we're left with an electrical problem. So I'm going to troubleshoot the left wow target light. So this lights, again, when you drop the entire bank of drop targets on the left-hand side of the play field. And the only way to light this lamp, first of all, you have to have your GI connection working. So your fuse has to be intact for that. And the second thing is the B relay. There's a normally open contact, which will close when that wow light is supposed to light up. So if it's not lighting, but I've completed the sequence, then I need to check the B relay. Now Gottlieb used these single and sometimes double letter abbreviations for units. and at a later date we'll get into what they are and why. But for now, just know that most other schematics, in fact, all really that I've ever read other than Gottlieb, have named units for everything. So each coil has its own special, unique function, and they do in Gottliebs as well. It's just that they use different abbreviations, basically. So here's an example. The K relay is actuated to increment 10,000. So you can see there's a logic, and they repeated this logic all the way through their EMs, and even up through System 1, System 80, and System 3 for certain relays that existed all the way up to the end. So Q is the game over relay or quit T is the tilt relay and so forth So armed with this knowledge you can troubleshoot practically any problem on an EM Now it can get hairy if there are many, many multiple switches or other units in the path, but for the most part, especially on a flipper game, you've only got a few different switches in any given circuit that are preventing or causing the errors. And with most any scoring problem if you've exhausted the relays then the next place to look is your score motor and the various contacts which are stacked up on that. We'll get into score motors at another time. So that brings me to my last point for tonight and that is the legend on each schematic. And that's going to vary by manufacturer as well. Here on this Gottlieb schematic, on the left-hand side, you'll see the letter for each relay laid out and what it does. So I can see that relay A is the alternating relay. Relay B is the number 2 through number 5 sequence relay. Letter C is number 6 through number 9 sequence relay. So those are obviously keeping track of the drop targets, as I mentioned. And then you have relays for the pop bumpers, points increment, ball return, all kinds of relays. And moving on from there, we've got abbreviations laid out. So if you see the letters R and O on the schematic, that means rollover. If you see POS, that means position. SW means switch, and so forth. And that leads us to one of the most important things, and that's the color code. So Gottlieb actually wrote a plain text color code. Other manufacturers used numbers to indicate what color the wires are in the machine. So looking at our fictitious right target switch, I had mentioned that one of the wire colors was yellow and blue. And that's because the schematic has yellow plus BL written. Now, if it was yellow minus BL, then it would be yellow with a blue tracer. And that's a tiny blue stitch in the wiring in a yellow wire. but this is yellow plus blue and that means that it is essentially alternating colors as it goes down so that's all for tonight thank you for joining me my name again is Nicholas Baldridge you can reach me at 4amusementonlypodcast at gmail.com you can find us online at 4amusementonly.libsyn.com and you can find us on iTunes, Stitcher, Pocket Casts RSS and Facebook thanks again, talk to you soon _(Acquisition: groq_whisper, Enrichment: v3)_ --- *Exported from Journalist Tool on 2026-04-13 | Item ID: 0f2be593-e121-4cdf-badd-126106b32138*