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Mike Gullo - Pinball Expo 2023 - Pinball News

Pinball News (Pinball Expo 2023)·video·58m 18s·analyzed·Oct 20, 2023
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claude-haiku-4-5-20251001 · $0.023

TL;DR

Technical service talk on pinball machine failures, repairs, and best practices.

Summary

Mike Gullo, an electronics technician with decades of experience, presents a technical service talk at Pinball Expo 2023 covering common failures and poor repairs he encounters while working on pinball machines at Pastimes Arcade. He addresses battery corrosion, crimping/connector issues, suboptimal workmanship (soldering, header replacement, flipper repairs), power supply problems, and burned components, offering practical repair techniques and service tips.

Key Claims

  • NVRAM battery eliminators eliminate battery corrosion issues and cost $25-30

    high confidence · Speaker directly states this is the solution implemented at Pastimes Arcade

  • Williams released a service bulletin to replace single 20-amp GI fuse with individual 5-amp fuses per circuit

    medium confidence · Referenced as historical service bulletin, not independently verified in content

  • Brazing with MAP gas torch and flux is inexpensive alternative to welding for flipper frame repairs

    high confidence · Speaker demonstrates technique and cost savings from personal experience

  • Newer Darlington transistors in System 3-7 driver boards allow replacement of large power resistors with 10K quarter-watt resistors

    high confidence · Speaker states this modification performed on every board at Pastimes Arcade with positive results

  • NTE53001 rectifiers (replacement for original 6-8 amp rectifiers) are becoming hard to find

    medium confidence · Observational claim about parts availability

Notable Quotes

  • “In keeping with the scary theme of the Halloween season, I thought I'd have some fun today and share some of the things that have horrified me in the past year or so.”

    Mike Gullo@ 0:27 — Frames the presentation as horror-themed retrospective on bad repairs

  • “They're about $25 to $30, no more batteries ever again.”

    Mike Gullo@ 8:39 — Key recommendation for eliminating battery corrosion problems

  • “I always twist my wire before I crimp them. And the reason is, there's a couple strands on the outside... you'll see those strands moving because it's crimping a bunch of miscellaneous strands.”

    Mike Gullo@ 13:38 — Detailed technical tip rarely discussed in pinball community

  • “What gives a flipper that strength to be able to do that is the mating surface between the shaft and the end stop. They need to be perfectly flat.”

    Mike Gullo@ 28:42 — Explains physics of flipper holding power and common repair mistake

  • “If you didn't grind all of that charred material away... you'll see arcing, you'll see fuses blowing, you'll see these same parts going bad again because that charred material will conduct if the voltage is high enough.”

    Mike Gullo@ 34:05 — Critical safety and repair principle for high-voltage boards

Entities

Mike GullopersonRob BurkepersonPastimes ArcadeorganizationPinball Expo 2023eventWilliamscompanyGottliebcompanyData EastcompanyBallycompanyMolexcompany

Signals

  • ?

    design_philosophy: Historical flipper end-stop design vulnerable to wear; flat mating surface critical but difficult to restore during repair

    high · Speaker explains flipper holding power depends on perfectly flat mating surface between shaft and end-stop; ground domes reduce contact area leading to chatter and reflip; recommends discarding worn components as regrinding cannot reliably restore flatness

  • $

    market_signal: NTE53001 replacement rectifiers becoming harder to source despite being standard solution for Bally rectifier board failures

    medium · Speaker notes 'getting to be a little hard to find now' when discussing NTE53001 as preferred replacement for original 6-8 amp rectifiers on Bally boards

  • ?

    community_signal: Speaker has developed systematic repair methodology including helper jigs for resistor bending and specific socket/fastener choices; treats each repair as opportunity to prevent future failures

    high · Multiple references to custom tools, standardized component choices, and preventive modifications; replaced transistors in every System 3-7 board; custom helper jigs for resistor bending

  • ?

    product_concern: Widespread poor repair practices in pinball service community including bad crimping, improper soldering, header damage, and unsafe modifications

    high · Repeated examples of 'suboptimal workmanship' including poorly crimped pins, wires soldered directly to boards, missing components, unsafe fuse bypasses, and inadequate flux cleanup

  • ?

    technology_signal: Battery corrosion remains pervasive problem in solid-state pinball despite decades of designs; NVRAM eliminators only recently adopted as standard solution at major arcades

Transcript

youtube_groq_whisper · $0.175

0:00
All right. So, hello everyone and welcome to my talk. As Rob said, my name is Mike Gullo. I think we were having audio issues earlier. This side of the room probably doesn't have any audio. Is that true? No, that's fine. Okay. So, can everyone hear now, even though was no audio on this side? Okay. So in keeping with the scary theme of the Halloween season, I thought I'd have some fun today and share some of the things that have horrified me in the past year or so. And along the way, I'll segue into some service tips. I'll explain how and why I would have done things differently in a lot of cases and how I repaired them. And I don't have a handout for this talk, but my plan is to have a Dropbox folder or a Google Drive folder. I'll have the slides from this presentation. I'll have some links to my favorite unique parts and tools, some miscellaneous service tips. In fact, all I need is email addresses if anybody wants access to that folder. I'm going to see if Rob can start passing this around. If you want access to it, I should have it done in about a week, and I'll share that with anyone that signs up. Sign up now because you may get halfway through and realize, hey, I want that part, and I didn't sign up to get the link to it. All right, thank you.
1:53
Before I get started, I'd like to take a minute or two just to give a brief introduction about myself.
2:00
I've worked as an electronics technician for several decades. I don't want to say how many. I've worked on pinball, yes, but also computers, computer servers, among other things. And I met Rob Burke about 15 years ago and began working on pinball machines in his home.
NTEcompany
McMaster Carcompany
Capcomcompany

high · Extensive photographic documentation of corrosion damage across Williams WPC, Gottlieb System 80, Data East, and other platforms; speaker states Pastimes Arcade 'switched over to almost exclusively NVRAM battery eliminators'

2:21
And now I'm pretty much semi-retired. I work on pinball machines at his new Pastimes Arcade in Ohio.
2:32
So let's get started. Aha, there's a reason why batteries and battery corrosion are considered to be the bane of solid state pinball, as we'll see from the first few slides. Yeah, Gottlieb System 80 with a lot of parts that need to be replaced. Yeah, the Williams System 6 driver board that's mounted right below the batteries on the CPU all the connectors there need to be replaced.
3:12
This is even an aftermarket battery holder on a Williams WPC system, and it's already broken and corroded everything below it.
3:25
This is not the same WPC board, but this is one of the few ones that I have a before and an after. A lot of parts there need to be replaced, and then after the white vinegar scrub and replacing these parts, it comes out looking like that.
3:48
Let's see, we have some more corrosion. Gottlieb System 80, interconnect. Molex discontinued these pins years ago, but someone has made an aftermarket version of these pins. I'm going to have a link to that in that Google Drive folder that I put together.
4:11
And here is the new shiny pins after they've been all replaced with the aftermarket ones. And it's easy enough to make your own extraction tool. I know they sell pin extractors for these, but it's easy enough to make your own instead of spending $20 to get a piece of spring steel that's ground to a certain shape.
4:34
If you have any old leaf switches around, you probably have some of the stiff spring steel pieces. Not the real thin, flimsy ones, but the more heavy-duty, stiff ones.
4:48
And if you grind it just a little bit narrower than you would for this kind of a connector, It will also work for the commonly used single-sided Gottlieb IDC connectors.
5:03
Getting these out is otherwise pretty difficult, but grinding that tip a little thinner will work in both.
5:15
So another Gottlieb System 80 board, and I'm going to zoom in just a little bit on this one. really every part on this board to the left of the processor needs to be replaced.
5:29
And the reason is when the battery corrosion starts working its way up the legs of those chips, working its way up the legs of those resistors, it's not going to just stop there. It's going to be inside all these parts.
5:43
And, in fact, when you start unsoldering these resistors, many of them, The legs will just break off the body of the resistor.
5:53
And this is the only board in this whole presentation that I have not fixed yet. And part of the reason is that it needs everything replaced. But part of the reason was when I flipped the board over,
6:06
this is what all the connectors look like on the back of the board. And cleaning these up, many of them probably wouldn't survive to the point of getting a good connection.
6:18
So let's move on to the ASIC chip on the WPC system. If you look on the bottom left, we can zoom in on the next slide.
6:31
Now you can start to see the corrosion there on the bottom left. And when I take out the chip and take the socket off the board, now you can see the corrosion. So we'll move on to a different WPC system. This one is actually a lot worse than it looks.
6:54
Yeah, the battery holder's corroded. I don't know if you can actually see to the right and to the bottom of the battery holder.
7:02
All that I count, one, two, three, four, five, six, maybe seven chips I had to replace, corrosion all the way up the legs. And this one required also probably replacing a couple dozen of those resistors. I don't know if you could see, but the corrosion's all the way up those two.
7:21
So this one's a lot worse than it looks. This one's not so bad. This is probably just one socket and one chip need to be replaced.
7:36
Okay, here we are again. A lot of parts on this one need to be replaced. Williams did move their battery holders eventually off the board, so when this happens, it doesn't require any other repairs on the board.
8:01
Yeah, here's a double row ribbon cable header and a couple resistor packs that need to be replaced. Another pretty extensive Data East corrosion problem. A lot of parts here need to be replaced.
8:22
So over at the past times arcade, we've switched over to almost exclusively NVRAM battery eliminators. How many people here have used those? So quite a few people, some people have.
8:39
They're about $25 to $30, no more batteries ever again. I would say a couple of the negatives are the price, $25 to $30.
8:49
Also, a lot of, well, I wouldn't say a lot. Some systems don't have their RAM socketed, so you would have to desolder the old RAM and put a socket in to use one of these. The third negative I can think of is any game that has a real time clock. WPC is a good example. The real time clock will only run while the machine is turned on. So we don't use the real time clock in any machines, but if you do, that would be a problem for these. And one other thing I'd like to mention about these NVRAM battery eliminators is They usually ship with a standard, okay, we'll back up one slide. If you notice, most of them come with round pins.
9:40
They're a little bit fatter than your standard IC, your standard RAM leg. And when you use a standard double wipe socket, and they even come with double wipe sockets, I'm a little worried about the fatter pin.
9:58
You're not going to be taking the chip in and out, but if you were, I definitely, every time I use an EnvyRAM battery eliminator, I always use the machine sockets.
10:10
They're a better fit for the pins. And they're a higher quality socket to begin with. They cost more, but I've never, ever had to replace one once it's in a game.
10:24
So I definitely use those with battery eliminators. Okay, we're moving on to the suboptimal workmanship category.
10:35
And with some of these pictures, I think you'll agree with me that I'm being a little charitable with that term suboptimal, as opposed to some of the other adjectives I could be using.
10:48
Now, here are some poorly crimped wires. This was actually an aftermarket add-on to a game that I was having trouble with. just wasn't intermittently working, barely working.
11:00
And once I took these pins out of the connector, I could easily see why. A little zoom in there. And this reminded me of Molex used to have 25 years ago. I don't know if they still have it on their website. They used to have this collection of sketches. It was called something like Anatomy of a Good Crimp, where they went into great detail showing bad crimps versus good crimps and explained why they were bad. So I found some of those old sketches that they had. This one is the anatomy of a pin, just showing the names of the different parts of a pin. We don't care about that. The fundamentals of a good crimp. But these next several slides actually do a little comparison of bad crimps versus good crimps.
11:59
Here, the bad crimp, the pin was not positioned correctly in your crimper. Let's see here. This one, the wire wasn't inserted far enough into the pin.
12:12
This one was, the bad one was crimped too hard. somehow the pin got bent while you were crimping it.
12:25
The locking tabs, that's not necessarily due to bad crimping, but something to keep in mind. This one's another one, an example of a pin not inserted properly in the crimper. and this one is the same except the opposite of the last slide. All these slides will be in that folder that I'm promising in Google Drive. So if we go back to that poorly crimped wire,
13:00
I wonder how many violations of Molex's crimping guidelines do we see in this picture. I can see a couple, at least, but a couple more tips that I have that I never hear anybody talk about,
13:17
and that is I always twist my wire before I crimp them. And the reason is, I don't know if you could see in this picture, but the wire that's coming through the crimped part of the connector, there's a couple strands on the outside.
13:38
Sometimes if you hold the pin, wiggle the wire, you'll see those strands moving because it's crimping a bunch of miscellaneous strands.
13:49
And always twist your wires before you crimp them, any kind of pin, any kind of connector. I can't think of one that I wouldn't twist. I never hear anybody talk about that. so the next thing about my crimping tips are to use a good crimping tool this one is a genuine ratcheting molex crimping tool probably 30 years old i use it every day uh probably 300 new um i get crimping tools like this over the years i get them on ebay They don't make these models anymore. The ones they make now are probably to and they much more specialized of crimping tools They for a specific type of pin as is this one But most of their older crimping tools crimp a pretty wide variety of terminals
14:44
And we're going to zoom in on the crimping section of it. But you can see this one, a good crimping tool crimps the insulation and the conductor part at the same time, one crimp.
15:01
Where most everyone, I'm sure, is familiar with the standard, also made by Molex, much more inexpensive, probably less than $20. Going back to these kind of crimpers, I suspect you can probably find them on eBay for $60 to $80. That's in the old days. That's what I would do when I would buy these on eBay. Just keep an eye out for them. If you're going to be doing a lot of crimping, highly recommended to get a good quality crimping tool. These kind do an adequate job, but if you're serious about crimping, I would get something better. Okay, let's Let's get back to our suboptimal workmanship. Here we have a broken fuse holder. Somebody decided instead of replacing this fuse holder, let's just put a screw in there and hold it to the still-existent half of the fuse holder. I don't think we need much explanation in how and why I would have done that differently. Here's another very common thing I come across. People get burned connectors, burned headers on boards, and they decide, I'll just solder the wires on the board. This one at least half of the wires, they put some sort of a connector there so you can at least unplug part of it. And here's the back of that same board. Some of the wires even went underneath and soldered on the back. I wish I could zoom in on the place there where they soldered those wires on because it's a very poor solder job. So this here was my repair. This is what it looks like after it's repaired. I have some certain techniques that we're not going to go into here, maybe next year, how I would actually replace these headers where there's no wires run on the bottom and you can't even tell they were repaired. So maybe next year we'll get more into that. Another thing I see far too commonly, people splicing wires where they don't even solder them together. And this one, I'll say that it is wrapped with electrical tape, barely. This might be an example of one of those boards that had the wires soldered on where the header used to be. Yeah, this was a chip. I don't know what board this is. Somebody replaced a chip at one time with extremely poor soldering skills, extraction skills I should say. Almost every pin had to be rerouted because the traces were damaged. And I don't have an after pick In fact, I may not have even fixed this because it was functional. But frequently I do repair these, and there's no more wires run after I'm done.
18:32
More soldering wires on two headers that were burned. How do you unplug this board if you need to work on the power supply?
18:47
Yeah, not much needs to be said about that one. So this was some suboptimal workmanship. It looks fine from here. Somebody replaced the relay on this one. Looks like it might have been out of a Williams game or maybe a Data East. But if we zoom in, you'll see the solder short. Now this is a mess. This one, somebody replaced a lot of parts. They didn't clean up the solder flux. So there are some reasons why I'm very diligent in cleaning up the solder flux. Number one, it looks better, and I like to take pride in my workmanship. But secondly, while solder flux is not conductive, there could be some impurities in that solder flux that do flow in between those pins. And most importantly, if you leave your work like this, how are you ever going to notice if you've done this on any of the pins?
20:11
You would never be able to see a solder short if you leave your work like this. So this was an example of a socket that I just replaced a few days ago. I added it to the slide because I thought, you know, we should have an example of a good socket replacement.
20:32
You know, everything's cleaned up, almost looks like factory. All right, let's move on to a different type of suboptimal workmanship.
20:46
Something else I see far too frequently, flipper end stops. People have stripped threads. They come with machine screws, 832 or 1032.
21:03
By the way, that would be a good time because I hear too often, I hear people call a 632 or an 832 screw 830 seconds.
21:18
And 830 seconds would be a quarter of an inch. But actually, the number 6 and the number 32, or the number 8 and the number 32,
21:27
the 6 and the 8 are just arbitrary numbers. The number 6 stands for an eighth of an inch in diameter, and let's see, an 8.32 would be 5.30 seconds. And the 32 part is just 32 threads per inch.
21:41
So don't call it an 8.30 second screw. Anyways, this is something I see far too common, a sheet metal screw replacing some stripped out threads in a flipper frame.
21:55
And, in fact, this one's even broken. Another thing that I see, let me go the other way. People use screws that are way too long. They'll use a sheet metal screw that's too long to even screw down all the way because it would come through the top of the play field. if they screwed it in all the way.
22:22
So what I've been doing an awful lot lately on a lot of flipper frames, I keep pushing the wrong button. I don't want to go that way.
22:34
I braze new nuts on the bottom. And I don't know how to weld. I'd like to learn how to weld someday. But I braze these with a torch. I've done it on flipper frames a lot recently I've done it on a lot of things and it's a much more inexpensive way than buying a whole welding set it's just a map gas torch that you get at Home Depot don't use the blue propane tanks but get the yellow map gas ones and a container of flux and some brazing rods and it's just kind of like soldering at a much higher temperature. There are some techniques you have to use to do it, but you can easily find a YouTube video that shows how to do that. I'll have links to the flux I use and the brazing rod I use. I get them from a company called McMaster Car. I don't know if anyone uses them for hardware or anything. I see some heads moving. They're great. And the problem with McMaster Car, if you want to buy a screw or a spring, get ready to filter out 50 different characteristics of that screw or that spring or that brazing rod or anything. So I've got links to some of these things that will be in my shared folder. So some more examples here. I don't remember what this was from, but it had some stripped screws, some stripped threads in the frame, and some new nuts got brazed on there. This is inside the nuts that hold on some pinball legs. And it may look like the brazing may not be as strong as welding. Do you have a question? Well, best for this would just be plain steel, but if you use zinc plated, generally heating it up, the zinc is going to be gone. So you're going to be left with the steel. I just try to start with steel right from the get-go. But brazing like this is extremely strong. I bet you could hardly knock these off with a hammer and a chisel. You would kind of have to grind them off in a lot of cases.
25:14
So, yes? Can you braze stainless steel? Yes, I have used this exact flux. And, in fact, I think we're going to, this next slide, this is a track from under a play field. Are those stainless steel, the tracks that are under the play field?
25:40
Okay. Maybe they aren't stainless steel. then I'm going to revoke what I just said about brazing stainless steel because there's certain things that I have brazed that I thought were stainless steel.
25:54
Maybe they weren't. This might have been one of them that I thought maybe it was stainless. So I'm not sure about that. I'm an electronics technician that does a little bit of brazing here and there, but I'm definitely not the brazing expert. So this one was just another example of how convenient it is to have this equipment. And it's inexpensive to have a set to do some brazing like this. This was an under play field track, and you could see the scoop in the middle.
26:27
Do I have, I don't think the pointer has a battery in it. Oh, it's coming. Oh, there's a switch. Okay.
26:38
Let's turn that on. Okay, there we go. So this whole half of the scoop was cracking across underneath where I brazed that metal on there. So I brazed a plate on there, and it's much stronger than it ever was from the factory.
26:57
And we're even going to zoom in. And it's not hard to do once you have a proper technique. Yeah, I think I could see this is not stainless steel. looking at it more closely.
27:13
Okay, back to suboptimal workmanship. Here's a flipper end stop. Yes? You can braze stainless steel. We heard it right here. You cannot braze titanium, but you can braze both stainless steel. Okay, okay, sounds good.
27:31
So here we have a flipper end stop. This may not be the best picture of what I'm about to describe here, somebody ground a dome on this end stop where the shaft meets the end stop. They also ground a dome onto the shaft. And, yes, I know you want to put a little edge on there so they don't peen over. But if you look in the middle, that little area there was the only mating surface between the end stop and the shaft. Why is that important?
28:12
Well, most everybody knows that a flipper coil, any older flipper coil, is two coils in one. It has a strong coil that flips when you first hit the button. The strong coil drops out when the end of the stroke switch opens, and then you're left with the weak coil. And with that weak coil only, you should be able to catch a pinball without having the flipper kind of like chatter and reflip.
28:42
Well, what gives a flipper that strength to be able to do that is the mating surface between the shaft and the end stop. They need to be perfectly flat. They need to have magnetism that actually holds those two in place. And this one the mating surface between those two is almost not even it just negligible So this flipper was it had very poor holding power If you tried to catch a ball it would do that exact thing It would collapse and reflip.
29:18
So I'm not sure a lot of people are aware of that, that those two, even when you're trying to repair one of these, it's very hard to grind or file them to a flat state so they'll have good holding power. So whenever they wear out, I say throw them away because you can't get them flat. Even if you can get them flat, they may not be perpendicular after you've ground them. So that's my tip there. Okay, now we're going to move into some, yeah, this is some of another thing I see very frequently. This looks like it's a bad solder job. Williams power supply, the general illumination 6 volts AC going into the power supply. This one, somebody over-fused it with a 30-amp fuse instead of a 20.
30:17
Williams released a service bulletin a long time ago to get rid of that 20-amp fuse and fuse each of the GI circuits through an individual 5-amp fuse. But this one still had a fuse on the board. There was a short on the GI line someplace, and the solder actually melted off the fuse, started dripping down the board, shorted out against the ground trace that goes around the outside.
30:48
Now the short is before the fuse. So this is the aftermath of this. and if you were anywhere within about 100 feet of this transformer when this happened, you would know this transformer is cooked.
31:08
Yeah, it was hard to get that smell out of the whole room. So another example of this. What value would you say that fuse is after somebody soldered a wire across it?
31:25
So this game here, that's another Williams power supply. This is the flipper voltage fuse. So this game, luckily it didn't happen, this game is one out-of-adjustment end-of-stroke switch from this.
31:47
There wouldn't be anything else to fuse it. So more suboptimal workmanship. This is what you see when somebody replaces parts on a board that doesn't have very good desoldering techniques.
32:06
They end up damaging a lot of traces and having to run wires to where the traces used to go. I don't have an after picture of this one, But I actually like working on these kind of boards. And like I said, next year, if Rob invites me back to speak again next year, I already have some new topics.
32:30
But this is one, repairing things like this so you don't have any more traces, any more wires run on the back of the board, any more unsightly wires run on the back of the board. Okay, this looks like a Capcom display voltage power supply, high voltage.
32:55
And the tip that I want to give today is this board didn't start out with the burns with that big of a holes. The burns, there weren't really even holes in this board when I started working on it. But what's important about this, if I go to the next slide, you'll see better.
33:19
That diode, you see a couple blue wires that I had to run to fix some burn traces and span that hole. But it's very important, if you have a board with any kind of burning or charring, you have to grind all of that away,
33:38
especially in a high-voltage application. This is a, yeah, I can see this is a Capcom. I can see the com stenciled on the board. Anyways, this is a display power supply. So it has over 100 volts. If you didn't grind all of that charred material away, as you can see I did, I actually made the hole bigger because I ground away all that charred material. You'll see arcing, you'll see fuses blowing, you'll see these same parts going bad again because that charred material will conduct if the voltage is high enough. It's not as important.
34:20
Yeah, well, that carbon, the burned part, conducts. So you'll see some arcing across some of that if you don't grind all that charred material away. Not as noticeable if you're talking about general illumination, 6 volts. but if you're any type of higher voltage at all, definitely grind all that away. It makes the hole bigger, but after you're done, I fill that hole with some silicone. I didn't do it in this picture because I wanted to show that I made the hole bigger by getting rid of that charred material.
34:55
So let's go on to, okay, we've jumped a category. We've gone to the burned category now. Yeah, this is a very common general illumination burn connector.
35:12
And another one. And in this next slide, I didn't have to work on the board that came off of here, a Bally-Solna driver board, but in the past at some time,
35:30
somebody must have had to do some extensive repair work on this board. It looks like it caught fire at one time.
35:41
This probably looks like the mating surface for maybe this one, not that one, the header. So I'd probably say I replace more headers on boards than anyone I've ever known.
36:01
Why do I keep pushing the wrong button? Let's go this direction. I'll get to more on the headers, but let's get back to burned here for now. So this connector here, you can see there is only one burned pin, and the wire has already been removed from that connector and soldered onto the board. But to fix this right, there's only one solution.
36:32
Re-pin every pin. There's 20-plus pins, but there's only one way to do it right. Replace the header on the board and get that pin back in here. Replace all the pins. Well, this is a burned PIC that I think everyone that's been in the older Williams systems has seen. The feature lamps, the power resistors burned up. This one, the board isn't as burned as it could be. But what I do, the reason why these burn is, and we'll get to it in the next picture. The reason why they burn is because the old transistors they used to use required a very high base voltage and current. We'll say the input voltage and current. So they had to have those big power resistors. Well, I've started converting all of our System 3 through 7 driver boards to newer transistors. I'm going to have a, this will all be in that folder that I'm going to send the links to of how to do this.
37:43
So now when you use these newer style Darlington transistors that don't need that high input voltage and current, you can get away with tiny resistors. I use 10K quarter watt.
37:58
And, in fact, I do so many of these. I made little helper jigs here to bend the legs of the resistor to the right spot. And I even have a spacer that I put under the resistors as I put them on the board, and I'll slide it out when I'm done because I do a lot of these. Every one that comes through gets this modification. and none of these parts even get warm anymore. Those resistors, you can't even feel that they're warm to the touch. The transistors, you can probably barely even tell they're on.
38:42
So we're going to move into another category. A lot of this next category could have spilled over into the suboptimal workmanship category, But I thought bally rectifier boards probably need their own category.
39:02
Here somebody has some of the wires soldered on. Some of the wires I think soldered went under the board and got soldered on. And they've replaced some bridge rectifiers and just left them hang there. Yeah, they are bigger than the original ones, but the original ones, you know, they needed to be screwed down as part of the heat sink. That plate behind there was a heat sink.
39:31
The heat sink may not be so important with these bigger rectifiers, but letting them dangle there is definitely not a good idea. Definitely suboptimal. this is the typical what I see a lot wires run underneath connectors cut off wires run underneath the board and soldered on the back and the next one the problem here this is the back of a Bally rectifier board the problem here may not necessarily this isn't from suboptimal workmanship like the other valley rectifier board picks are. This one, if we zoom in, this is the line fuse holder, the 3-amp line fuse holder.
40:22
No wonder the game was shutting off regularly. But back here you can't even really see it. So, okay, we even have more here. Do you ever put the rectifiers on the other side of the board and just put heat sink fins on them? No, I will show you though what I do shortly when I fix them and I've never had a recurrence. I do see that sometimes. In fact, sometimes I've seen people put 35 amp rectifiers on the front of the board with a heat sink on them. I have seen people do that. I've never done that. I think I have a little description here of what I do coming up in a couple slides. Yeah, here we just have more of the same. And Rob, I hope you give me a little signal if we're running short on time. I wanted to leave a little bit of time for questions, but we want to be out of here because the next speaker comes in right at 2. So give me a heads up at whatever time you think I should go to questions. Okay, so more wires soldered on the burned headers, burned connectors and burned headers. Here's one that I finished. This one has all the headers replaced and it has all new 10
41:52
amp rectifiers. NTE makes a replacement for the originals which were either 6 or 8 amps. I don't even remember if they were six or eight. So NTE makes a replacement. They're getting to be a little hard to find now, part number NTE53001. They're a little thicker.
42:12
I've seen people use those and only replace one, and they're a little bit thicker. So the board is now spaced out further, and the other two rectifiers you can't screw to the heat sink. Sometimes I've seen people use a washer to try to make the old rectifiers a little bit taller so they do mate. Then you have heat going through multiple surfaces. You already have a plate back there it has to go through to get to the heat sink.
42:45
So whenever I replace one with the NTE version, I replace them all. And I've never seen one of these fail. They are a higher power than the original ones. and you probably know that the one that fails the most is the 43 volt rectifier the one that runs the solenoids and specifically the flippers i think it fails most because people don't know how to adjust end to stroke switches and they over fuse the five amp solenoid fuse but I think this is a permanent solution instead of going to the 35 amp rectifiers and this is the these are the standoffs I like to use as opposed to the ones that just lock in I like to use nylon standoffs and it easy to take this rectifier board off You know I only screw those nylon spacers kind of finger tight as tight as I can get them with my finger, but still be able to loosen them up.
43:58
And let's move on to headers. Like I said, I probably replace more headers than anyone I've ever known. So why do I replace so many headers? If you ever have a header that's had wires soldered onto it, that header needs to be replaced. Even if you clean up the solder,
44:23
there's still going to be a coating of solder over those pins. And solder oxidizes quickly. If you clean it up, it'll conduct fine for now, but it oxidizes quickly.
44:37
So solder is not a good mating surface for a contact. So I would replace all these headers. They've had wire soldered on.
44:47
Another header that I would definitely be replacing, most of the headers are, I believe, bronze pins with a tin plating. And once that tin plating starts wearing off, now this connector needs to be cleaned anyways. And cleaning this connector would remove a lot more of that already failing tin plating.
45:11
So I wouldn't even try to clean this. This would get replaced. Here's one that might actually look nice and clean and shiny, somewhat shiny. but this had a stiff wire brush used to clean the pins, and it leaves a lot of grooves and scratches, horizontal grooves and scratches across the pins. So another type of header I like to replace are the old Williams headers with round pins.
45:48
And in the next slide, I'm going to show why I would replace those. I made these sketches. Now I'm not a graphic designer, so you'll have to forgive my crude sketches. But this is an example of two mating surfaces. If you have a round pin trying to mate with a flat contact in a connector, you can see the mating surface is very small. In the upper right, you see this one that has grooves all over it.
46:23
Once again, in the upper right, that mating surface is very limited because of those grooves. And of course, on the bottom, if you put a new header in, now you have the full surface of both the terminal and the pin on the header, in the header, mating nicely.
46:47
So let me go back here. I jumped two slides. A lot of people have probably had intermittent solenoid fuses blowing.
46:59
And I've actually seen this happen a couple times in the last couple weeks. Same issue, intermittently blowing a solenoid fuse. Don't know why, don't know which coil is doing it, but once you figure out which coil is doing it, this is what you see sometimes. the winding of the coil is exposed. And one time that this happens frequently is if you have a coil, some coils are fatter than others, even at the same gauge wire and windings, that they just naturally kind of sit almost against the frame. And if you ever have a coil that's not mounted tightly, maybe the holder or the end stop is a little bit loose, or if you don't have the wave washer in there and the coil itself can slide around back and forth, that's when you'll get this rubbing happening and the trace shorting out against the flipper frame every now and then, intermittently blowing fuses.
48:14
Okay, now this capacitor here looks like it's about to blow. And the high voltage capacitor on an old Bally solenoid driver board looks like something's growing out of it. So I discovered this transformer. I don't even remember what this was in. Maybe it was in a Bally Rectifier board with the lugs broken off. And you know, transformers are hard to find replacements for. They're very specialized and they're just hard to find. So I repaired this one and the next slide, we're going to go into some detail how I did this. You can see that the tiny wires that used to go to those lugs are still there. They're just broken off the dangling lugs.
49:20
So what I did first was to attach some wires to those dangling wires, make them a little bit longer.
49:33
Then I loosely fit those lugs back where they used to go. wrapped the wires around them, and soldered them.
49:44
And I like to use a glue called E6000. In this pick, I glued them back in place with E6000. I love E6000. If you go to any craft store, Michael's, I can't even remember what some of the other craft stores are. They sell E6000. I think Home Depot and Lowe's even sell it now. So I use that a lot for these kinds of repairs. I use silicone glue also, but for this I wanted something a little bit stronger.
50:18
Okay, this next slide is going to require a little explanation. This board was, in fact, this board was purchased for Rob Burke's whitewater in his basement. Rob had a whitewater in his basement, and the waterfall effect, the chase effect on the topper, the control board was missing.
50:44
So I found an aftermarket board online. I'm not going to say who we bought it from. We ordered an aftermarket board. It was supposed to be a direct replacement of the original.
50:56
And the board arrived. I installed it. and within a few seconds, maybe several seconds, I could smell a burning smell.
51:09
And I shut the game off really quickly, and it was pretty obvious that this new board, at least some of the transistors were shorted out. So we sent it back to who we bought it from, went back and forth for a long time until we finally got a replacement.
51:27
So we got a replacement. In the interim, I checked all the lamp circuits. There were no shorts. We put the new board in.
51:39
Within a few seconds, the burning smell was back. Most of those transistors are shorted out again. So I took the board back to the workshop. I made a little test harness for it with no load. And I got out my oscilloscope and started doing some troubleshooting. I got out a data sheet that had the pinouts of these transistors.
52:09
And after replacing them, they didn't go bad again because I didn't have a load on them on the bench here. But I could just tell something was not working properly. And if you look at the next pick, well, I don't know what could be wrong. They're installed properly, but the thing is the stenciling on the board was backwards.
52:35
I determined that all 16 of these transistors were bad every time I turned it on because the stenciling on this board was done backwards. All these transistors were installed backwards on both boards right from the aftermarket supplier, and I suspect we contacted them.
52:58
Five minutes? Okay. Let me skip ahead and see if there's anything else that I want to cover. Well, you know what? This will be a good time to end and take some questions because the next thing I wanted to cover,
53:16
this will be a good preview for my talk next year if Rob invites me back. I wanted to do a talk, a DIY talk, about making test fixtures, making little test jigs, making pin extractors. I'd like to do a whole talk about that. But in the background of this, this will be my preview for next year's talk, in the background of this pic is a WPC test fixture that we built. Let me go to the end. this was a homemade WPC test fixture. And I'd like to go through step-by-step how we did this, but you'll have to come back next year for that. And there's other little things that I make little testers for. I made a tester for a Gottlieb pop bumper board tester.
54:09
But that's all you get to see for now. You have to come back next year to see much more, much more DIY.
54:16
So we have questions. Do we have questions? First of all, let's go over here. You're talking about solder with antimony? Typically, lead-free solder is antimony. I used to use it a long time ago. I never noticed any issues like reflowing solder joints with it. I don't use it anymore. I've gone back to using solder with lead in it. I never noticed any issues with it when I used to use it. So my anecdotal evidence would be to say there was not a problem with it. Is that the type of solder you're talking about? Yeah, okay.
55:03
I don't know the answer to that. That's a good question. They are? Okay. If they're exporting to Europe, that's what you said? Okay.
55:18
Okay, and you had a question. Yeah. Oh, that's true. That's a very good point. Let me see if I can go back, because I want to supplement what that question referred to. Let me see if I can find it.
55:49
Yeah, that's very, yeah, this right here. A lot of newer boards are multi-layer boards. So they'll have two, three, four layers stacked in there. If you have one of those boards, you wouldn't have been able to do this. In fact, if you had a board with multi-layers, let's see, this, You wouldn't have been able to grind that away because you would have destroyed traces that run through those inner boards. It's not just a ground plane. There could be a lot of layers that have other traces in there. So you have to make sure your board is a single layer. If you hold it up to light, you'll be able to tell. You'll be able to see typically the traces that are run on the back if you hold it up to light. If you can see those traces, you can know it's a single-layer board. But you're right, that's a very good point. If you have multi-layers, you cannot fix this kind of charring.
56:48
One more here. Do you have a favorite piece out of the tool? Yes. In fact, I have it with me out there in our booth that I'm going to be doing some repairs. I like the HACO system. I don't like the pistol type.
57:06
I like the pencil type. I use a HACO, I think the number is 1091, but the other number is 8. Now I can't remember what the number is. Yeah, I've always used HACO for many, many years. And parts, you know, they discontinue models. So once again, you have to find your replacement parts on eBay. Sometimes Amazon even sells them. In fact, I just bought some Hakko tips, some Hakko extractor tips from Home Depot, from the Home Depot marketplace, some of the tips.
57:48
I wish I could say the number of the pencil type, but I don't like the pistol type. I guess maybe because I just haven't been used to using it.
57:58
So do we have any more questions? I think we're about out of time, right? We're about to move to the next. That's why you're here chasing me away. So thank you all for coming, and hopefully I'll see you next year at the DIY Talk.