# Part 7: 1978 Gottlieb Close Encounters of the Third Kind Project. Ground & Fuse Mods!

**Source:** Pinball Shenanigans  
**Type:** video  
**Published:** 2025-10-14  
**Duration:** 27m 48s  
**Beat:** Pinball

**URL:** https://www.youtube.com/watch?v=uxy3PhCSSgg

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## Analysis

Mike Dus continues restoration of a 1978 Gottlieb Close Encounters of the Third Kind pinball machine, installing ground mods and fuse modifications to improve electrical safety and reliability. He performs playfield repairs (lane guides, drop targets, slingshot switches), conducts a play test that reveals a malfunctioning roto wheel mechanism and non-responsive targets, and experiments with a Lizzy board (Raspberry Pi-based MPU replacement) as an alternative control system.

### Key Claims

- [HIGH] Ground mods and fuse modifications are highly recommended and should be performed on Gottlieb System One machines — _Mike states these are standard recommended modifications for System One machines; fuse mods protect the small transformer_
- [HIGH] The roto wheel mechanism on Close Encounters requires cleaning and maintenance before effective play testing can continue — _During play test, roto wheel fails to spin properly and all playfield shots trigger it, blocking progression; Mike identifies it as gummy and needing cleaning_
- [MEDIUM] Lizzy board (Raspberry Pi-based MPU) can serve as a functional replacement for original Gottlieb control boards — _Initial testing shows Lizzy board boots properly, recognizes game ROM (Close Encounters 969), maintains credit memory, and triggers solenoids; however, lamp control is non-functional_
- [HIGH] Corey Cook (London Pinball) provided technical guidance on power supply ground mod connections using resistor continuity — _Mike explicitly credits Corey for identifying R8 resistor continuity point for grounding on driver board power supply_

### Notable Quotes

> "I got to say this close encounters is really coming along and looking real nice."
> — **Mike Dus**, ~0:45
> _Expresses satisfaction with overall restoration progress before detailing technical work_

> "These godly system one machines... ground mods are highly recommended. And I haven't done this before, add in a couple fuse mods to help protect the small transformer. It's a thing that you're supposed to do, you should do, and is a good thing to do."
> — **Mike Dus**, ~0:30
> _Establishes that ground and fuse mods are best-practice maintenance for System One Gottlieb machines_

> "I don't really think we can get too far with play testing until that [roto wheel] is addressed. Everything triggers the roto wheel."
> — **Mike Dus**, ~26:00
> _Identifies roto wheel as critical blocker for meaningful playfield testing; indicates design where most shots activate this mechanism_

> "If someone walks up to the game, plays it, it destroys them in 12 seconds with three balls, then they might not be interested in buying it. But if you got five cracks at it, oh, then, you know, might be a little more desirable."
> — **Mike Dus**, ~30:45
> _Explains business rationale for configuring machine for 5-ball play before selling at November 16th, 2025 Fork River pinball sale_

> "Everything is functional except for the roto target and these switches that are tied to it... kind of getting close. We're probably like 80% there."
> — **Mike Dus**, ~31:30
> _Assessment of overall restoration status; identifies roto system as remaining critical issue_

### Entities

| Name | Type | Context |
|------|------|---------|
| Mike Dus | person | Content creator for Pinball Shenanigans; restoring 1978 Gottlieb Close Encounters, performs hands-on electronics and playfield work |
| Corey Cook | person | London Pinball; provides technical consultation on ground mod electrical connections and MPU repair services; Mike has borrowed two of his control boards |
| Dave Susa | person | Mentioned as source of technical knowledge about Lizzy board boot times (~30 seconds) |
| Close Encounters of the Third Kind (Gottlieb 1978) | game | Pinball machine being restored by Mike; features roto wheel mechanism, drop targets, spinner, slingshots; planning to sell at Fork River November 2025 |
| Gottlieb System One | product | Platform/architecture of Close Encounters; subject of recommended ground mods and fuse modifications for electrical safety |
| Lizzy board | product | Aftermarket MPU replacement using Raspberry Pi; Mike testing as alternative to original Gottlieb control board; boots Close Encounters ROM code, recognizes game, triggers solenoids but lamp control non-functional |
| Raspberry Pi | product | Computing platform used in Lizzy board system; requires ~30 second boot time |
| Fork River | event | Pinball sale scheduled November 16, 2025; Mike plans to bring Close Encounters machine for sale |
| London Pinball | company | Corey Cook's pinball repair/restoration business; provides MPU boards and technical support |
| Pinball Shenanigans | organization | YouTube/video series hosted by Mike Dus focusing on pinball machine restoration projects |

### Topics

- **Primary:** Gottlieb System One electrical modifications (ground mods, fuse mods), Classic pinball machine restoration and maintenance, Roto wheel mechanism repair and troubleshooting, Aftermarket control board alternatives (Lizzy board/Raspberry Pi-based MPU)
- **Secondary:** Playfield component repair (lane guides, drop targets, switches), Play testing and quality assurance for restoration projects
- **Mentioned:** Commercial sale/operator preparation of machines

### Sentiment

**Positive** (0.75) — Mike expresses satisfaction with restoration progress and problem-solving approach. Frustration emerges during play test when mechanical issues are discovered (roto wheel, stuck targets, non-responsive switches) but is pragmatic about identifying solutions. Optimistic about Lizzy board potential despite lamp control issue. Overall tone is educational and methodical rather than discouraged.

### Signals

- **[community_signal]** Peer-to-peer technical support network evident; Corey Cook providing specialized guidance on electrical modifications, Mike consulting technical forums before proceeding with modifications (confidence: high) — Mike credits Corey for ground mod resistor identification; posts in 'pinball repair help group' to verify power supply grounding approach before energizing machine
- **[operational_signal]** Ground mods and fuse modifications established as standard recommended maintenance for Gottlieb System One machines to improve electrical safety and reliability (confidence: high) — Mike describes ground mods and fuse mods as 'highly recommended,' 'a thing that you're supposed to do,' and protective of transformer; follows published modification guidance for lug connections and fuse ratings
- **[product_strategy]** Lizzy board tested as post-release upgrade to control system; lamp driver board integration issue identified requiring further troubleshooting (confidence: medium) — Mike reseated lamp driver connectors but lamp control remained non-functional; suspects connector or ROM variant issue; plans further research; success in other areas suggests design viability
- **[product_concern]** Manufacturing/design issue identified: roto wheel mechanism on Close Encounters exhibits gummy operation and requires significant cleaning; affects playfield progression as multiple shots trigger it (confidence: high) — During play test, roto wheel fails to spin despite solenoid firing; all playfield shots (lanes, target, spinner) trigger roto when they shouldn't; Mike identifies as design/maintenance issue requiring disassembly and cleaning
- **[technology_signal]** Lizzy board (Raspberry Pi-based MPU replacement) demonstrated as functional alternative to original Gottlieb control boards; Mike testing as potential replacement for multiple original MPUs (confidence: high) — Lizzy board boots Close Encounters 969 ROM successfully, recognizes game state, maintains credit memory, triggers solenoids; only lamp control circuit non-functional. Mike states intention to return Corey's borrowed boards if Lizzy board proves reliable.

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## Transcript

I'm Mike Dus and this is Pinball Shenanigans. [Music] Yo, what's going on? It's October 13th and it is beautiful out still, but winter is coming, so I have to work over at the garage as much as I can before it gets too cold. So, going to head over there, work on some close encounters. What I want to do today is add the ground mods that is highly recommended for these godly system one machines. And I haven't done this before, add in a couple uh fuse mods to help protect the small transformer. It's a thing that you're supposed to do, you should do, and is a good thing to do. So, I'm going to do it. And then maybe after I uh do the less fun stuff, we're going to play a game. I got the tripod. We'll set it up and give it a first real play test and then uh create a to-do list of what needs to be done playfieldwise. Switches, drop targets, roto spinner, whatever. So, that's the plan. We'll see you over there shortly. I got to say this close encounters is really coming along. and looking real nice. But before I get to the ground mods, there's a couple things I want to do. I've got a bit of a problem here with my lane guides. They are broken. So, one thing you could do is somehow get a new one. Somehow get this piece that's broken off in here out. Maybe punch it through and then reinstall. But, uh, I'm not going to do that. I'm going to try the super glue method. Just going to load it up with super glue right here at the junction point and just hope that holds. I mean, they don't pop up during gameplay. At least they haven't. So, I'm thinking some super glue might be sufficient. And then while that's drying, I can do the ground mods. And then by the time I've done the ground mods, we should be able to play a game without messing with the lane guides. And one other thing I found in my stash, this lane guide here. And I'm going to replace this guy cuz it's actually in two pieces. You can see the crack there. And it's broken here. I mean, this one's kind of broken. And this one's kind of broken, too. But this one's really broken. And I happen to have a new one, new used one. So, I'll pop that on there. And one other thing, install a new shiny ball. And we can get rid of this old Nasty one. Okay, one dab will do you. Once that hardens, that should be good to go. All right, there's the old lane guide. And there's the new one. Much better. Okay. To add the additional ground to a nywamp board, it is suggested to scrape off some of the masking. I think Joshua Clay Herurl said to do it on the front side of the board, on the negative side of this capacitor here, but maybe that's a different variation of a Nywump board because I don't think if I scrape the front side of that much good is going to come of it. So, what I can do though, as you can see, the negative leg of the capacitor right there. If I just scrape some of this masking off here with my knife, then I can solder the wire right to that spot, I think. You know what? That connects right to here. I could just probably solder right to these guys. So, that should work. Okay, my uh utility knife wasn't really working all that great. So, I just took my Dremel to that spot. Cleared off some of the masking, soldered my wire to it, and then I soldered one of these guys onto the other end. And then, uh that'll probably end up potentially there. See if I left myself enough wire. Well, would you look at that? Just the right amount of wire and doesn't look too uh doesn't look too bad either. Looks like it belongs. So, good to go there. Now, got to find a good spot for ground on this power supply because usually attach it to the negative side of this capacitor, I think. But since this is um radial and not axial, I don't have access to the legs. the leads. So, I got to figure out something else here. Okay, driver board ground mod is done. And you tie the wire into the negative lead of this capacitor. Scraped off some of the uh Sorry, my headlamp when I hit record looks like a freaking disco. Doesn't look like that in real life though. Only through the camera. But yeah, scraped off some of the the green stuff with my Dremel, soldered the wire onto it, and connected it here. So, that one's done. Okay. Where I have the black lead is where the negative lead of the capacitor originally went. And with the help of Corey Cook of London Pinball, he uh said that R9 here Oh, I didn't turn on my multimeter. Anyway, that has u continuity from that resistor to that spot where the capacitor leg was or still is just on the back side. And also this R102 here that had continuity and also R8 on the left side here. So, I went with R8 and connected this wire to here. So, now that's grounded. I don't know if that's uh going to be a problem at all, but I posted it in the pinball repair help group just to make sure that, you know, that is actually okay. I think it should be, but we'll find out soon as I turn on the machine and see an explosion. Okay, so Gotly didn't add fuses where they probably should have and they eventually did for the small transformer. So, this is a recommended modification to do. It seems simple enough. Haven't done it before. So, you cut off this blue white wire on lug six. Make sure you got lug six here. What is that? Four. Six. 13. Doesn't help when people paint over the numbers. And then you attach it to a fuse clip. Get a piece of wire. Attach it to the fuse clip. And then this wire goes back to the lug. And you pop in a fuse. Just uh got to find out which type of fuse it is. And then screw this into the bottom board. And then uh rinse and repeat for the other fuse. There might be three that I need to add total. So, we'll uh do some reading and make sure um I get it all figured out and sorted out here. Okay, that wasn't so bad. So, just remember log six and 2 amp slowblow fuse and then that is done. So, next one is lug seven, which in this case is white brown wire. And then we need a 3/4 amp fuse for that. Can't remember if it's slow blow or not, but uh I'll check that out in a moment. Okay, so that is done. That is a 3/4 amp fast blow fuse. And I think this ultimately becomes 12 volts or something. And this I don't even know what they are really. I just follow the instructions and do the recommendations. Um there is one more fuse that I do need to add cuz it doesn't have it. This is I guess the 115 volts coming into the transformer. So that is what this clip is for. And that is going to be a 1 amp slowb blow fuse. Except the battery on my um portable soldering iron is starting to go. So I don't want to start the process and then not be able to finish because then I can't play test. So I'll come back with a fresh battery. But uh other than you know hunching over the machine for half an hour, it ain't so bad. You could obviously remove the whole bottom board and put it on a bench and make life a little bit easier, but uh it ain't so bad. So, ground mods are pretty much done. I guess I could do the soundboard, but again, lack of battery and fuse mods are uh almost done. So, I think it's time to play test. All right, let's give this thing a play test. I got my pen and paper ready to go to write down any issues that may pop up. Oh, and on a side note, these uh ball guide rails seem to be uh pretty uh in there. So, I think they should not be a problem. All right, so here goes nothing. We'll see if we have the issue where the ball doesn't kick all the way over into the shooter lane occasionally. I think that's a gotle thing. I've had that on other games before. Fresh rubbers. All switches cleaned up. Spinner lubed. Hey, [Music] didn't get a hit there on my roto wheel. You know what? I still have to kind of deal with the roto wheel like clean all the targets and deal with whatever is going on over there. It's like trying to spin. Like I hear the solenoid firing, but it ain't spinning. So maybe it needs to be sort of latched into the home position before it'll spin. Find out right here. Should spin now, I'm going to guess. There we go. And probably will not spin. Hey, there's that new switch on the slingshot here. That worked. Let's see if this fails. Yeah, did not work. I was assuming I was going to have uh some issues with the roto. I'm excited to work on that mech. I watched a couple videos. Looks like a ball of fun. But definitely needs some love. Oh, is this set for five balls? Yeah, it looks like it is. I'll have to change that. Although, it's been pretty evil. So, I don't think my uh 10point switch here was registering. Let's try this. What? Why aren't you registering? Okay, let's try the other 10point switches. Not not not. Okay, that usually means that one of them is stuck closed and then they're because of that they're all not working. What about this guy? Oh, he's up there, Billy. Come on now. Slow down there. Hello. Fly. Stop it. that is not playable. Okay, and that target is sticking. See that? Under the plastic. So, I need to add a a washer underneath those guys. All right, my list is uh getting pretty big already. All right. My method for uh checking all of the rebound switches is uh to look from the underside. You can look from the top side, but you know, it's more telling from the back side. So, I shine a light through. And then I have a look and you can see that those two switch contacts are not touching. Let's see if I can find another example here. How about this guy? You can see they're clearly not touching. So, I went through all of them. And there's one over here that the lug was kind of bent over a little bit. So, maybe that was the problem. The lug was touching the other lug or something. But other than that, I don't see any issues. So, we'll give that a try. I did resolve this target here getting stuck. I just added a washer here and loosened this guy off a little bit. And that ain't going to get stuck anymore. Okay, have a look here. Much better. I actually removed the washer. I didn't really need it. I just needed to ease this off a little bit. I had it a little too far down and that was the issue. There's tons of clearance. I don't want to hit that because that's going to cause the roto to go into uh angry mode. I think it's just really gummy and really needs a cleaning. So, I'll have to deal with that another day. But check this out. Our rebound switches are working again. So, it must have been just that one switch where the lug was bent over a little too much. But that is good to go. I can cross a couple things off my list so far. Okay. I don't think I can really do any more effective play testing without uh addressing the roto wheel first cuz everything triggers the roto wheel. Spin roto. Right roto target value. Okay, that's not a spin though. So both inlanes spin the roto. All the upper lanes spin the roto. The target spins the roto. This lane spins the roto. So I don't really think we can get too far with play testing until that is addressed. But nonetheless, let's see what happens now. Oh, wait. Shut up for a minute. I don't understand why none of the roto switches are working though. Like, yeah, I get that it doesn't spin. But why are my targets not registering? Not hitting it hard enough. Or are they just really super gummy? Am I just missing them all together? That's my problem. I do want to get a good couple spinner rips and some drop targets. Uh yeah. Well, that's weird because before I was pushing in on the targets. I was trying to like check all the light bulbs and uh they were registering before. But anyway, that that thing is a mess. So, what I can do probably next time is literally turn the playfield upside down and rest it in the cabinet. With these Gotle System ones, you can do that pretty easily. And uh then I can work on it a little easier. But who knows? Maybe I'll have to take the whole route out back home so I can really clean it properly. The old laundry tub. How did I light the spinner? And like I said, I want to see some Hey, that switch didn't work. Okay. What about this one? Ooh, I think that's tied into the roto targets themselves cuz that's supposed to do roto value. So, I bet it's not the switches per se that is the issue. It's the whole freaking rout. Okay. So, what am I on? All three. See if I can knock down the drop targets and maybe light the spinner. You have to hit ABC. Two drop targets left. That did not light my spinner. Uh, and this going to reset all of my drop target progress. Ball four. If I am going to bring this to the uh pinball sale that we're having at Fork River, November 16th, 2025. Then I think I will actually leave it on five balls because if someone walks up to the game, plays it, it destroys them in 12 seconds with three balls, then they might not be interested in buying it. But if you got five cracks at it, oh, then, you know, might be a little more desirable. Oh no, I'm not quitting. Two more drop targets left. This the old 710 split. Uh-oh. Oh, okay. Thought the uh MPU froze up on me. Let's just uh hit start. Wait. Oh, okay. We're all good. We're all good. Drop targets are still happy. But okay, I think I am probably going to wrap it up after I hit these draw targets. [Music] [Laughter] I think everything is functional except for the roto target and these switches that are tied to it. So, kind of getting close. Kind of getting close. We're probably like 80% there. So, I think that's a good point to uh wrap up for today. We'll see you on the next one. Bonus footage. I decided before I go, I want to actually try out this Lizzy board now that I got my Raspberry Pi in there and my SD card. That way, I know I have a good MPU because I still have two of Cory's MPUs and I should get them back to him at some point. So, if this works, then I'd say between that one and this one, I'm probably safe to return Cory's board. So, let's try this Lizzy board for the first time in 3 2 1. All right. What are these lights saying? Need my glasses. Where are my glasses? Oh, here they are. Uh, it says switches is good. Whatever that is. And whatever that is. 5 volts. Looks good. What's it saying? Closy 969 boot. Oh, what was that all about? Well, let's hit the start button. See if anything happens. 3 2 1 Oh, I think we have zero credits. So, let's remedy that. Whoa. Interesting. That's kind of cute. All right, here we go. Three, two, one. [Applause] Got a different sound package. Okay, this Lizzy board is probably not going to like the roto wheel getting all crazy from time to time, but everything seems to be good so far. Let's h give her a whirl. And I'm starting to wonder if this is even the correct game ROM. Although I do have it set for Close Encounters. It did try and spin the roto when it hit the switch up there. So maybe that's right. It's kind of doing what it's supposed to be doing except for the fact we have no playfield lights and the sounds are very bizarre. Gotly system one sounds are pretty meh to begin with. So I don't know that this is any better or worse. Actually, is it just the same tone? No, there's there's different tones. [Music] Okay. Well, [Music] I guess I have uh some more research to be doing on this Lizzy board, but other than lights, I think everything's working okay. So, that's not bad. Okay, so this chip says solenoids and lamps. So this connector could be suspect cuz it goes to driver board and these are all the lamps. So I don't know something to do with that. I receeded it. I receated these two guys just in case. Unfortunately, that didn't solve the problem, but it is kind of cool. I kind of didn't catch this the first time, but it says Lizzy 1 9:00 a.m. EO4, wait for Pi. So, got to wait for the Raspberry Pi to boot up. So, it's informing you to do that. And that reminds me, I think Dave Susa told me that takes like 30 seconds for these things to boot up. So, be patient. And then it doesn't say close something. It says come on pie getting impatient. Hello. It's been like oh there close encounters 969 boot 52888. I don't know what any of that means but it's definitely on the right code. So that's pretty cool. That works. And it saved my credit. So memory is working. Start up a game here. [Music] So the only thing is that I got no lights. Wow. GI just no controlled lamp. So I checked all the fuses just in case and was definitely not the issue. So I'll have to look into that. But this Lizzy board has promise, so I should probably return Cory's boards. Anyway, I think that's about it for now. We'll see you next time.

_(Acquisition: youtube_auto_sub, Enrichment: v3)_

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*Exported from Journalist Tool on 2026-04-13 | Item ID: 733fc510-c52c-4c97-a62e-d23983a0a61f*