# Part 11: 1985 Pinstar Gamatron Project! I get the playfield connected! Signs of life!

**Source:** Pinball Shenanigans  
**Type:** video  
**Published:** 2025-09-19  
**Duration:** 37m 17s  
**Beat:** Pinball

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

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## Analysis

Mike Dus continues restoration of a 1985 Pinstar Gamatron pinball machine, focusing on power supply diagnostics and MPU installation. After identifying a faulty voltage regulator component (RP1/RP2 bridge rectifier hybrid), he successfully replaces it and achieves proper 7.8V output. He then installs the Weebly MPU, lamp driver boards, and playfield, achieving initial boot-up with functional general illumination, solenoids, drop targets, spinners, and basic gameplay mechanics, though some systems (flippers, certain displays) still require wiring corrections.

### Key Claims

- [HIGH] RP1/RP2 components are hybrid half-bridge rectifiers used only in Kiss, Future Spa, and Space Invaders machines for powering extra lamp effects — _Mike explains the specialized power supply design used in only three Gottlieb machines_
- [HIGH] R712E components cost approximately $15 USD each plus shipping/taxes — _Mike states he found them available at Marco Electronics_
- [HIGH] The faulty voltage regulator was causing 3.6V instead of required 5.4V at test point one — _Direct measurement during troubleshooting sequence_
- [HIGH] Replacement RP1/RP2 component brought voltage up to 7.8V under no-load conditions, which Mike considers acceptable — _Post-installation voltage testing_
- [HIGH] MPU connector pins required repinning due to burnt wires and improper crimping — _Visual inspection and manual connector rework shown in episode_
- [HIGH] Weebly MPU board was configured for Flight 2000 with free play and S1/B1 CPU clock jumpers set correctly — _Mike manually verifies DIP switch and jumper settings against manual_
- [HIGH] Initial power-on achieved general illumination, solenoid firing, and basic gameplay (spinners, drop targets, ball scoring) — _Live testing sequence showing functional mechanics_
- [HIGH] Flipper solenoids are not yet wired, preventing flipper functionality — _Mike notes flippers aren't responding and suspects incomplete wiring_

### Notable Quotes

> "So, where are the schematics for that? They're they're kind of weird components. I don't even really know what they're called, but I think I have the schematic pulled up here."
> — **Mike Dus**, Early in episode
> _Illustrates the specialized knowledge required for Gottlieb system repairs and the challenge of working with obscure components_

> "So, you know, that particular power supply is only used in like three games, Valley Kiss, Future Spa, and Space Invaders. And the reason they used those particular boards is because those machines had some extra lamps that did some fun dancing around and light shows."
> — **Mike Dus**, Component explanation section
> _Demonstrates deep understanding of Gottlieb design choices and engineering constraints_

> "I'm not exactly looking forward to it. Looks like a pain in the butt, but I want to get my voltage proper, so it is a necessary evil."
> — **Mike Dus**, Before component replacement
> _Reflects the methodical, persistence-focused approach to restoration work_

> "Woo! General illumination. That's kind of exciting."
> — **Mike Dus**, First power-on after playfield installation
> _Captures the emotional payoff of successful systems activation_

> "Holy We have a tracked mode and it looks awesome. But oh, display number two is kind of showing high score to date. And we got some flickerage."
> — **Mike Dus**, Post boot-up gameplay testing
> _Shows progress with functional core systems despite minor display issues_

> "So, no. We got to like lock balls by doing things... Anyway, this is uh How about that? Oh, nice."
> — **Mike Dus**, Multiball and flipper testing section
> _Documents the iterative testing process discovering which mechanics work and which need more wiring_

> "There's probably going to be a few more episodes, like 50, but I am determined and stubborn. And I am going to fight tooth and nail until I get this thing to function as it should."
> — **Mike Dus**, Episode conclusion
> _Expresses long-term commitment to full restoration despite acknowledging substantial remaining work_

> "So, we'll make it happen one way or another. But I'd say that is a pretty good uh notch in the progress for tonight."
> — **Mike Dus**, Final remarks
> _Acknowledges the significance of reaching playfield-connected milestone_

### Entities

| Name | Type | Context |
|------|------|---------|
| Mike Dus | person | Host and primary restorer of Gamutron project; experienced pinball technician with deep component-level knowledge |
| Corey Cook / Corey | person | London Pinball operator/technician providing remote diagnostic assistance via testing guidance |
| Henry Mastenardi | person | Friend who provided donor Kiss pinball machine board with reference R712E components |
| Ellie | person | Dog/pet present during restoration, provides comedic relief and 'inspection' commentary |
| Gamutron / Gamatron | game | 1985 Pinstar custom/homebrew pinball machine being fully restored; primary subject of episode series |
| Pinball Shenanigans | organization | YouTube video series documenting the Gamutron restoration project |
| Gottlieb / Gottlieb System One | company | Manufacturer of 1985 Pinstar Gamutron; referenced for schematic and component design knowledge |
| Weebly Board / Weebly MPU | product | Aftermarket MPU replacement board installed in Gamutron for control logic and boot sequences |
| SB-300 / Viper Soundboard | product | Sound board from donor Viper machine; available but not yet installed in this episode |
| RP1/RP2 Components / R712E | product | Specialized hybrid half-bridge rectifier components used only in Kiss/Future Spa/Space Invaders; faulty component replaced at approximately $15 each |
| Kiss / Future Spa / Space Invaders | game | Gottlieb machines using identical RP1/RP2 power supply design for extra lamp effects |
| Flight 2000 | game | ROM/software configuration reference used for Weebly MPU DIP switch settings |
| Marco Electronics | company | Supplier of R712E replacement components |
| PinSide / Pinball Repair Help Group | organization | Online community forums where Mike seeks and shares restoration advice; mentions other Gamutron builders |
| MCR 105/106 Lamp Driver | product | Replacement lamp driver board installed after original had broken leg |

### Signals

- **[community_signal]** Active use of PinSide and Pinball Repair Help Group for remote diagnostic assistance and knowledge sharing (confidence: high) — Mike explicitly mentions Corey Cook assisting via testing guidance, plans to follow up on repair group, references other Gamutron builders using similar Weebly/SB-300 combination
- **[design_philosophy]** Achievement of functional core mechanics (solenoids, drop targets, spinners, ball scoring) on first playfield power-on after extensive troubleshooting (confidence: high) — Initial boot produces GI lighting, solenoid firing, ball walker operation, drop target scoring, spinner scoring, all without prior playfield installation
- **[product_strategy]** Generic LED adapters mentioned as forthcoming upgrade to address light failures (confidence: medium) — Mike notes 'half of them [lights] are not working' and mentions 'Siegecraft or generic LED adapters coming, so don't worry'
- **[restoration_signal]** Sequential board-by-board power-on testing approach with voltage validation at test points before proceeding to next component (confidence: high) — Mike tests rectifier board first, then solenoid driver, identifies voltage failure at test point one (3.6V vs 5.4V required), removes and tests suspected components, replaces R712E, revalidates voltage before MPU installation
- **[technology_signal]** Multi-step iterative troubleshooting demonstrating deep component-level knowledge and refusal to accept partial solutions (confidence: high) — Mike backtracks to test R712E components despite them testing 'fine componentwise', replaces instead of troubleshooting further, methodically repins entire MPU connector rather than working around burnt wires
- **[technology_signal]** Multiple systems require component replacement/repair: R712E regulator, lamp driver with broken leg, connector repinning, incomplete flipper wiring (confidence: high) — Mike identifies and addresses voltage regulator failure, broken lamp driver leg, burnt wires in MPU connector, and missing flipper solenoid wiring connections

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## Transcript

Okay, I think I found a compromise. Two chairs. I'm Mike Dus and this is Pinball Shenanigans. [Music] Okay, Gamutron episode 11. I'd like to see if I can install the MPU tonight. Kind of sequentially going through the boards. We got the rectifier board. up and running. We got the solenoid driver board up and running. Next will be MPU. But since I'm not getting the proper voltage at test point one, I thought before I go ahead, I would go backwards. And so I did some more testing with the help of Corey Cook of London Pinball. And although everything tests fine componentwise, I'm still getting a low voltage on my test point one. That should be 5.4 volts. I'm getting 3.6. And the only thing that makes sense from the schematics and our testing and you know, we've pretty much concluded that it's got to be one of these two guys. So, where are the schematics for that? They're they're kind of weird components. I don't even really know what they're called, but I think I have the schematic pulled up here. So, let's go to that. So, you know, that particular power supply is only used in like three games, Valley Kiss, Future Spa, and Space Invaders. And the reason they used those particular boards is because those machines had some extra lamps that did some fun dancing around and light shows like on Kiss. Can you picture behind the Kiss letters? There's some dancing lights. Same with Future Spa and Space Invaders maybe for the Infinity Lights. So that's why they used that particular board. They only used it in those three machines. On the normal machines, they just use the three standard bridge rectifiers. On these boards, they use whatever the hell these are called on the schematic. They're referred to as RP1 and RP2. So, those are the two components on the top of my board. They combine to make one bridge rectifier, basically. So, they're like half bridges. They combine two halves to make one full bridge. I have read that you can replace the two things with one actual standard 30 amp bridge rectifier, but I don't know that I'm going to try that. It requires some drilling and some jumpers and whatnot, but I for sure I'm getting good voltage coming out of the transformer. It's supposed to have 9.2 I'm getting like 10 point something. So I have concluded that I have to remove and test those things. So I have the board kind of sort of just out like this. And you know you can test them pretty much like bridges. And they do test fine which is annoying. But my thing I just have to remove them and see what happens. They do test. Actually, you know what? I found this board. This is I think was given to me by my buddy Henry Mastenardi. Shout out who um gave this to me from his old KISS machine. These whatever you call them are obscure. Well, you can get them at Marco. They're like 15 US each. So, you know, that's going to add up in a hurry with shipping and taxes, etc. But R712E, that's what I need if uh those test bad. So they do test differently on this board than they do like I get a reading. You hold them one leg to here or one lead to here and one to here. And then you do that on this side on the board in the machine I get a reading of like 0.5. But on this I get five and then open. And then if I reverse it I get 0.5 and then open. So they do test differently. I don't know what it all means. But, you know, I have a couple of these if I need to uh try and replace one or both.
I'm not exactly looking forward to it. Looks like a pain in the butt, but I want to get my voltage proper, so it is a necessary evil. So, this is the band-aid I'm going to tear off before I do the more fun MPU stuff. So, I'm going to hack away at this for a bit. I'll report back. Okay, so I removed the transformer assembly from the machine. And then I removed one of these things from the board. It wasn't that bad. Just got to remove a couple screws and nuts and the heat sink. And then I did the same on Henry's board. And here is the one that came from his. So I found some interesting results. I will show you. Okay. So I don't really know how to test these. I just do every possible combination and kind of just figure it out. So, let's start with the good one here. We'll put black here and red here. We get a reading of 549. If I go over here though, I get nothing. You get nothing when you do that. Nothing when you do that. But then you switch the leads. So, this should be nothing. But on this side I get 0.54 and over here it's good reading. So I do get something different here. Get the good reading on this but I get nothing on that. So, I'm starting to think that this guy is in fact bad. So, the only way to find out really is to install this guy and then retest voltages. So, I'm going to do that. Okay. I think I had a successful surgery. This is the new guy here. And um just note to self if I have to replace that one too when bending the leg back over the back side cuz I you know you have to straighten them out to remove them. These legs are bent over. So uh when I rebent it back down I almost thought it broke. So that would have sucked. So keep that in mind if you ever run into this issue. But now for the test. and pray. Okay. DC voltage. Got my ground here. All right. What do you think? Is it going to work? What's the over under on this? Okay, here we go. Oh, wait. What? Look at that. 7.8 seems kind of high, but it ain't low. So, I think we have success. Like, is 7.8 good, though? I mean, we supposed to be a 5.4, but I guess it's not under load, right? So, I'm going to call that a success. And I will um uh follow up on my post on pinball repair help group. Let them know what I did and uh just double check that that voltage is okay, which I am pretty sure it is. So, sweet. We don't have to deal with the other guy. And uh now I got to remember to put my screws back in my bridges. And uh then we can move on to the MPU. Okay, time to install the MPU. Just kidding. I was just looking at this connector. And uh look at that. One pin there is coming up. Oh, that looks like that was actually repinned, So, I think I need to repin this connector. Just Wow, look at this red wire. That is burnt. Maybe cut off a little bit of the old crappy wire. I mean, I don't have a whole lot of play here, so can maybe afford an eighth off of each wire, but it's about it. But yeah, I think uh I can't leave that as is. Okay, progress is being made. Show you the difference here. The right side, starting from this orange wire, they're all done. You can see how shiny the pins are. And you can see how there's not wire strands hanging out. Uh like on this side far left here, you can see some wire. Red, yellow, you can see some wire. And red terminal is pooched. It's just falling out of the connector. See, look. They have wire past the entire terminal. That terminal is supposed to be crimped onto the insulation. So, also these were not trifuricon terminals. So, they're getting a multi- beneficial treatment here. So, almost halfway there. Okay, I just went and had a panerati break. I'm back and I finish the job here. That red one looks like it wants to be pushed down just a tiny bit more maybe. But repin 2025. Much better. I don't even know that I'll be able to stick this on onehanded, but definitely lost a little bit of my slack here. So, I'll plug that in and then we're going to stick in an MPU. Maybe stick in a playfield. I don't know. We're just flying by the seat of my pants here and uh things are starting to happen. Okay. Uh the inspector's calling. Hold on. Is it okay? What do you think, Ellie? Yeah, I know. It's not in the greatest condition. Are you taking over my chair again? Someone said in the comments that this was Ellie shenanigans, and I would say it sure is. You just do your thing. All right. Go check out uh the desk and all that. Yeah, that transistor is bad or whatever the hell it's called. But anyway, okay. So, definitely needed like two hands to force this connector on cuz it is snug with all these new connectors. And you got to kind of like sometimes this one's also really snug cuz it's repinned. See that? You know what? Let's just leave it on there. But sometimes if it's so snug, kind of forces the wire back out a bit. So you just to be safe, push these wires in after you've connected it. I do that from time to time. There we go. So, I had to like remove my zip tie or wire tie, whatever you call it. It's just a little tight. So, I just added some zip ties and that'll suffice. I can leave it like that, I think. I don't know. Uh I just like there to be a little bit of slack. So, anyway, that's done. I'm going to snip those off and then uh grab this uh Weebly MPU. Right, Ellie? Yeah, but the Weebly MPU is right here. You want to change the dip switch settings for me? Oh, don't step on these. They could be sharp. You might not like that. Let's put that there where maybe you're less likely to stand and step on it. Okay. So yeah, we got to change some dip switch settings and uh check my Okay. Okay. Okay. Okay. Okay. Let's Let's not step on that board. That was my fault. I'll put it up here. There we go. Okay. Um change some dip switch settings. Check the jumpers. Make sure they're they're on stern and not bally. and uh check the standoffs. Make sure the old ones are okay. If not, we'll install new ones. Can you get your butt out of my face, please? Sometimes you're the inspector. Sometimes you're the helper. I know. I know. Okay, so that's the plan. Um once Ellie gets off my lap. Okay, I found a compromise. We each get a chair. All right. So, weebly board manual. And here's our settings. So, flight 2000. We could do stock ROM with no free play, but I'm going to go with the free play. And that means our dip switches need to be on, off, on, off, off, on, on on, on, out. Wait, hold on. That's too many dip switches. That's the clock jumpers. So, on, off, on. Oh, Ellie's coming back to my lap. Oh, no. She's heading out. Okay. Okay. Where are we? Game selection on Off. On. Okay. And then off. Off. On. On on on. [Music] I think I had this in my Viper before. So, it's probably set to that. So, on, off, on on. These are so hard to see. On, off, on, off, off, on, on on, on. Okay, as for the jumpers, CPU clock jumpers, B1 and S1. We want S1 in. So, that is over here. See that S1 jumper's already on that. It's got to be on those two pins there represented by that little triangle. Otherwise, if you want Bali-1735 or Stern MPU 100, you move the jumper down to this position. So, that's good. And then, um, what's this all about? All off. Off is bal and MPU 100. All on slash in is MPU 200. That's what we're doing. So we want all on, which looks like they are. Yep. Okay. So, our Weebly board is set. All right. I got the MPU installed. Got that connector installed. That connector installed. And then I installed this guy on the solenoid driver. Oh, I forgot to clip these guys off. Where's my clippers? So, I'm going to um power this thing on Might not be a whole lot of anything. You know what I should do? is throw in at least a bulb or two because there are zero in the back glass backbox. And be nice to know if we have life back there. So, let's install a few bulbs. I have no idea if these bulbs are even good. But I figure one out of four should be uh okay if I can find the one I dropped. So, are we going to get backbox lights? Are we going to get displays? This display is disconnected. I'll leave that disconnected for now and uh see what happens. Okay, put this guy back in. All right. Three, two, one. One, two, three, three, four, five, six, 7. I think that means we're booted up. And uh I'm cheating a little bit. And I can kind of see some display activity. See what we got. Wow, we got a couple displays. No bulbs though. And the displays are just kind of locked on. So, I feel like uh we're moving in the right direction. So maybe um maybe I need the lamp driver board installed. No, that wouldn't help. That wouldn't matter for general illumination, right? And this I should be careful that it's not grounding out to anything. Oh, also this could be something to do with the backbox lights. What if I try and make contact here? Anything happen? Uh, don't think so. Okay. Um, let's install a lamp driver board. Okay. So, my note says that this lamp driver is from Supersonic and is okay, but that is not true because this guy has a broken leg. I don't know if it's used for sure or not. But I think I'm just going to go ahead and replace that before I install this. All right, there we go. This is an MCR 105 or maybe 106. I couldn't really see. And think I got it facing the right way. Looks different than the others, but it should work. So, we can find out pretty easily what Q56 lights up. And if it's not lighting up, then um I did something wrong. But I think it should be good. Okay, lamp driver is installed as well as those two connectors. And then I installed this other display just to see what would happen. And uh let's turn it on and see if anything different happens. And oh, I see some glow. Okay, little bit of life on that display, but no backbox lights. Oo, is that a cut right here? What is missing here? There should be Okay, this is probably disconnected on purpose. What are those lights? I don't know. Why would you disconnect those? And some wire was in here. and just like yeah it doesn't look like there's continuity for the GI backbox lighting another okay so these guys were in that clip there um yeah so this probably part of the equation anyway I think maybe we could plug in some of this stuff and see what happens. Also, I do have an SB 300 sound board. That is part of the equation when not using the uh Gamatron board. Says original Viper soundboard was working fine in Viper. maybe had some speaker buzz. So, I might have to um install some standoffs or something to hook this board up, but I don't know if I'm going to I don't really care about sound at the moment. I want um everything else that's kind of later down the line. And I don't really feel like messing with standoffs right now. So, where does this all go? That goes here. So, I don't know. Should I just throw in the uh playfield and start connecting more things? Sure, why not? Let's just keep plugging away. All right, time to install the playfield. This is a bit of a momentous occasion. So, I think I have to record it. Obviously, it'll be in time lapse because uh it's going to take me a minute or two, but it'll be very nice to get this space back, too. So, that'll be added bonus. Okay, I changed my mind. I think because I have enough wire here, I can actually just install the playfield and keep it on the rotisserie just in case I need to deal with stuff. rotisserie wise may I mean like I can lift up this playfield pretty high and gain access to most of it pretty comfortably but I'm going to do this because I can. So I'm just going to start connecting stuff and then we're going to turn this on and see what happens. All right, playfield is technically connected. It's definitely a bit of a mess. Because this connector says J2 solenoid driver unit, which means I guess this guy is not used. These four wires, ABCD, connect to these four wires. And since that's going into the solenoid driver, I'm assuming these are for solenoids, but I could be wrong. I could check the schematics and see. Um, so yeah, this is unused. This would be for the other kind of power supply that BY used. Also got some wires coming off this connector. So there's a lamp driver, new lamp driver connector here. Here's the old one. So I guess that's not used. So maybe these wires here potentially connect to these wires there. And then this is for the gamutron board. And this these two connectors are for the gamutron board which we're not using. And yeah, so I don't know what the f is going to happen if anything at all. But we're going to turn it on and find out. So, let's just tear off the band-aid in three, two, one. Woo! General illumination. That's kind of exciting. Oh, wait. Hold on. Could we have a track mode perhaps? Hey, solenoids are firing. The ball walker mech is looking for balls. That's pretty cool. Displays are still doing stupid things. So, this machine wants to see three balls and maybe then it will go into a track mode. Oh, wait. It gave up. Holy We have a tracked mode and it looks awesome. But oh, display number two is kind of showing high score to date. And we got some flickerage. But I got Siegecraft or generic LED adapters coming, so don't worry. Man, a lot of lights not working. Like half of them. This drop target bank did not reset. Well, let's throw in some balls and just try and start a game. You think that would actually happen? Oh, remember I got to solder this onto the diagnostic switch. So, it's technically on free play, shall we? Whoa. Wow. Okay, let's plunge the ball into play. Do that. Oh, look at that. We got points. 3,000 5,000 3,000 Okay, let's try this pop bumper. Wow. Hey, and the drop targets popped up. They're scoring. They're resetting. What about slings? Wow. Spinner. That is scoring. What about these guys? They never did rebuild these drop targets. They're scoring. Okay, ready. This is a big one. Sweet. Wow, that's violent spinner. That's scoring. What about this? What happens? Nothing. Okay. Why nothing? Oh, because I need to install this switch. Let's hit it. Boom. And ball kicks out. Let's try that again. And boom. Ellie. Oh, sorry. Didn't mean to scare you. This is exciting stuff.
Yeah, I know. I'm excited, too. And ball kicks out. can we get a multiball? Go in there. You go in there. You go in here. Oops. You go out here. Okay. So, no. We got to like lock balls by doing things. Wow, that's violent. It's going to like pop right off the freaking rotisserie. Anyway, this is uh How about that? Oh, nice. That slingshot works, too. Oo, sling to the drop. Oh, what about flippers? Let's try some flippers. Okay, ready? Ooh, maybe that's the solenoid wiring I got to do. Okay. Well, I'd say that's uh way better of a start than I thought it was going to be. So, uh I guess I will uh maybe work on these wires, connect those, and see if that gives us flippers. Okay. just been sitting here contemplating, staring at success here to some degree. And I think my game plan is going to be to uh install reinstall that broken wire for the diagnostic tests and maybe run through diagnostics. I really should connect those four wires though. the Kevin had to disconnect these. They were hardwired, so they definitely do something. So, maybe I'll do uh it'd be nice if I could turn that into a connector and not have to hard wire it. So, I got to sort that out and I'll be back. Okay, I soldered this back up and through the balls in the trough. so that the ball walker ain't looking for the balls for five minutes. And let's power this on. Run a couple tests and then I actually think I'm going to wrap it up. Starting to run out of gas here. I'm yawning away. Look at that. Isn't that pretty? So maybe only two lights out actually. That ain't so bad there. I thought there was more out there. Okay, let's hit the button and see if anything happens. Did it show the old high score to date? Oh, look at that. Both displays are working okay now. And the bottom one. Oh, it's just missing two digits. That's repable. Actually, I'm not going to be using these, but it's good to have spares. Six-digit spares. All right, let's see what happens if we do this. Oh, no. No. I'm just mashing on it. And so, I don't know if that's a wiring thing or a button thing, but I guess we could jumper the switch. That will help to diagnose. It's not the best tool for the job here. And nothing does appear to be happening. I think it's going to be a very steep uphill battle from here on in. This was probably the easiest part of the whole process. So, there's probably going to be a few more episodes, like 50, but I am determined and stubborn. And I am going to fight tooth and nail until I get this thing to function as it should. If it's the last thing I do, called it, stamped it. No erases. And you know, there's a lot of great help out there on Pinsside, Pinball Repair Help Group, people that have scratch built gamutrons using the same Weebly SL uh Stern 300 soundboard combo. So, we'll make it happen one way or another. But I'd say that is a pretty good uh notch in the progress for tonight. So that was pretty sweet. We'll see you guys next

_(Acquisition: youtube_auto_sub, Enrichment: v3)_

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*Exported from Journalist Tool on 2026-06-06 | Item ID: 2ea4639f-bdcd-431e-bd41-1fcbdd064a59*